Page 1
FOREWORD
This service manual is written to familiarize you with the maintenance of your L-series Diesel Engine. If the engine is
carefully maintained, it will deliver a long productive life and efficient performance marked by power and economy.
Before attempting to inspect, disassemble, or repair the engine, read this manual carefully to learn more about the
engine and how to care for it properly. All descriptions, illustrations, specifications and serial numbers in this manual
are effective as of the date of printing of this manual.
The information contained in this manual applies to the engine model produced at the time of publication. It should
be noted that specifications and design may change due to improvements made thereafter.
What this manual covers
This service manual covers standard specifications for the L-series Mitsubishi Diesel Engine, and describes
• Specification
• Maintenance standard
• Adjustment
• Disassembly, inspection and repair
• Reassembly
In addition to the Summary of Manual Contents, a short summary of contents is found on the first page of each
group of the manual.
Operation and periodic maintenance are described in the Operation & Maintenance Manual, component parts and
ordering of service parts are described in the Parts Catalogue. Structure and function of the engine are described in
the various training manuals.
How to use this manual
1. Parts in illustrations are numbered to correspond with references to those numbers in the disassembly
sequence.
2. Items or conditions to be inspected during disassembly are enclosed in a box in the disassembled views:
3. Clogged oil hole
4. Maintenance standards for inspection and repair are described in text where they are relevant. For a quick
summary of maintenance standards, refer to group 9 of this manual.
5. Tightening torque under wet conditions is indicated as “(wet)” in text, drawings and tables. When so indicated as
(wet), apply engine oil to the threaded portion of the fastener. Unless indicated as such, the tightening torque is
to be assumed in the dry condition.
6. Measurements are based on the International System of Units (SI), and they are converted to the metric and
English system units in this manual based on the following conversion rates.
• Pressure 1 Mpa = 10.197 kgf/cm
• Torque N·m = 0.10197 kgf·m
• Force N = 0.10197 kgf
• Horsepower 1 kW = 1.341 HP = 1.3596 PS
2
Service Manual
Mitsubishi L-Series diesel engines
Version 08/2004
Copyright © 2004 MHI Equipment Europe B.V.
Service Manual Mitsubishi L-Series diesel engines
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Page 2
WARNING SIGNS
The following safety related signs are used in this manual to emphasize important and critical instructions:
Indicates the most serious specific potential hazard which could result in
serious personal injury or death.
DANGER
Indicates a specific potential hazard which could result in personal injury.
WARNING
Indicates operating procedures, practices, etc. which could result in personal
CAUTION
injury or damage causing destruction to the engine. Some of the CAUTION
signs also indicate a specific potential hazard which could result in serious
personal injury or death.
Indicates procedures, conditions, etc. which are important to highlight.
NOTE
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Page 3
TERMS USED IN THIS MANUAL
Before reading this manual, note that the following special terms are used in dimensional and other specifications.
Assembly standard
Indicates the dimension of a part, the dimension to be attained at the time of reassembly or the standard
performance. The value is rounded to the nearest number needed for inspection and is different from the design
value.
Repair limit
A part which has reached this limit must be repaired.
Service limit
A part which has reached this limit must be replaced.
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Page 4
SUMMARY OF MANUAL CONTENTS
Section Contents
1. General Engine model and engine number, external views, features, engine specifications,
maintenance, troubleshooting
2. Engine main parts General, rocker arms and rocker shaft, cylinder head, valves and valve springs, inlet manifold
and exhaust manifold, gear case and oil pump, timing gear, camshaft (valve camshaft and
injection pump camshaft), piston and connecting rod, crankshaft, cylinder block
3. Lubrication system General, oil filter and oil pressure switch
4. Fuel system General, fuel injection pump, injection nozzle
5. Governor system General, torque spring
6. Cooling system General, fan and fan belt, water pump, thermostat, water temperature gauge unit and
thermoswitch
7. Air cleaner Air cleaner
8. Electrical system General, starter, alternator and dynamo, glow plug, key-off stop system, glow timer system
9. Service
specifications and
standard
Periodic service chart, specifications and standards, tightening torque chart and sealant chart,
special tools
Table 1 Sections in the service manual
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Page 5
TABLE OF CONTENTS
TABLE OF CONTENTS
GENERAL
1 ENGINE MODEL AND ENGINE NUMBER........................................................................ 12
1.1 Model, classification and use ................................................................................................. 12
1.2 Engine model embossment and engine number stamp......................................................... 12
2 EXTERNAL VIEW ..................................................................................................................... 14
2.1 Engine L2............................................................................................................................... 14
2.2 Engine L3............................................................................................................................... 15
3FEATURES................................................................................................................................. 16
3.1 Aim of development ............................................................................................................... 16
3.2 Features of the new series..................................................................................................... 16
4 SPECIFICATIONS..................................................................................................................... 18
5 MAINTENANCE......................................................................................................................... 19
5.1 Engine oil and oil filter............................................................................................................ 19
5.2 Retightening the cylinder head bolts...................................................................................... 21
5.3 Adjusting the valve clearance ................................................................................................22
5.4 Adjusting the fan belt tension................................................................................................. 23
5.5 Bleeding air from the fuel system........................................................................................... 23
5.6 Replacing the fuel filter .......................................................................................................... 24
5.7 Checking and adjusting injection timing................................................................................. 26
5.8 Adjusting the engine speeds..................................................................................................27
5.9 Checking and adjustment of nozzles ..................................................................................... 28
6 TROUBLESHOOTING ............................................................................................................. 31
6.1 Hints on using the trouble-diagnosis chart............................................................................. 31
6.2 Hard starting .......................................................................................................................... 32
6.3 Knocking ................................................................................................................................ 33
6.4 Overheating ........................................................................................................................... 34
6.5 Black-smoky exhaust ............................................................................................................. 35
6.6 Unsteady idling ...................................................................................................................... 36
6.7 Low output ............................................................................................................................. 37
ENGINE MAIN PARTS
7GENERAL.................................................................................................................................... 40
7.1 Specifications......................................................................................................................... 40
7.2 Special Tools ......................................................................................................................... 41
8 ROCKER ARMS AND ROCKER SHAFT........................................................................... 42
8.1 Disassembly........................................................................................................................... 42
8.2 Removal and installation........................................................................................................ 43
8.3 Inspection............................................................................................................................... 43
9 CYLINDER HEAD ..................................................................................................................... 44
9.1 Disassembly........................................................................................................................... 44
9.2 Removal................................................................................................................................. 45
9.3 Inspection and Repair ............................................................................................................ 46
9.4 Replacement of valve guide...................................................................................................46
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TABLE OF CONTENTS
9.5 Repair of valve seat ............................................................................................................... 47
9.6 Installation.............................................................................................................................. 48
10 VALVES AND VALVE SPRINGS ......................................................................................... 49
10.1 Disassembly........................................................................................................................... 49
10.2 Removal................................................................................................................................. 50
10.3 Inspection and repair ............................................................................................................. 50
10.4 Installation.............................................................................................................................. 51
11 INLET MANIFOLD AND EXHAUST MANIFOLD............................................................. 52
11.1 Disassembly........................................................................................................................... 52
11.2 Inspection............................................................................................................................... 52
12 GEAR CASE AND OIL PUMP............................................................................................... 54
12.1 Disassembly........................................................................................................................... 54
12.2 Removal................................................................................................................................. 55
12.3 Inspection............................................................................................................................... 55
12.4 Replacement of front oil seal ................................................................................................. 56
12.5 Replacement of governor shaft bushings .............................................................................. 56
12.6 Inspection of governor system ...............................................................................................57
12.7 Disassembly and reassembly of governor levers .................................................................. 57
12.8 Installation of gear case assembly......................................................................................... 58
13 TIMING GEARS ......................................................................................................................... 59
13.1 Disassembly........................................................................................................................... 59
13.2 Removal................................................................................................................................. 60
13.3 Inspection............................................................................................................................... 60
13.4 Installation of timing gears ..................................................................................................... 61
14 CAMSHAFTS (VALVE AND INJECTION PUMP)............................................................ 62
14.1 Disassembly........................................................................................................................... 62
14.2 Removal of Valve Camshaft .................................................................................................. 63
14.3 Inspection............................................................................................................................... 64
14.4 Installation.............................................................................................................................. 65
15 PISTON AND CONNECTION ROD...................................................................................... 66
15.1 Disassembly........................................................................................................................... 66
15.2 Removal................................................................................................................................. 67
15.3 Inspection............................................................................................................................... 68
15.4 Installation.............................................................................................................................. 69
16 CRANKSHAFT........................................................................................................................... 73
16.1 Disassembly........................................................................................................................... 73
16.2 Removal................................................................................................................................. 74
16.3 Inspection............................................................................................................................... 74
16.4 Replacement of crankshaft rear oil seal................................................................................. 76
16.5 Installation.............................................................................................................................. 77
17 CYLINDER BLOCK .................................................................................................................. 78
17.1 Disassembly........................................................................................................................... 78
17.2 Inspection............................................................................................................................... 79
17.3 Reboring of cylinder ............................................................................................................... 79
LUBRICATION SYSTEM
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18 GENERAL.................................................................................................................................... 82
18.1 Specification........................................................................................................................... 82
18.2 Special tools........................................................................................................................... 82
19 OIL FILTER AND OIL PRESSURE SWITCH.................................................................... 83
19.1 Disassembly........................................................................................................................... 83
19.2 Removal and installation........................................................................................................ 84
19.3 Inspection............................................................................................................................... 84
FUEL SYSTEM
20 GENERAL.................................................................................................................................... 86
20.1 Specifications......................................................................................................................... 86
20.2 Disassembly........................................................................................................................... 88
21 FUEL INJECTION PUMP........................................................................................................ 89
21.1 Disassembly........................................................................................................................... 89
21.2 Inspecting the injection pump while operating the engine ..................................................... 90
21.3 Removal................................................................................................................................. 90
21.4 Disassembly........................................................................................................................... 90
21.5 Inspection............................................................................................................................... 91
21.6 Reassembly of plunger .......................................................................................................... 91
21.7 Reassembly of delivery valve ................................................................................................91
22 INJECTION NOZZLE ............................................................................................................... 92
22.1 Disassembly........................................................................................................................... 92
22.2 Removal................................................................................................................................. 92
22.3 Disassembly........................................................................................................................... 93
22.4 Inspection............................................................................................................................... 94
22.5 Assembly ............................................................................................................................... 94
22.6 Adjustment ............................................................................................................................. 94
22.7 Installation.............................................................................................................................. 95
GOVERNOR SYSTEM
23 GENERAL.................................................................................................................................... 98
23.1 Specification........................................................................................................................... 98
23.2 Disassembly........................................................................................................................... 99
24 TORQUE SPRING................................................................................................................... 100
24.1 Installation of torque spring set ............................................................................................ 100
24.2 Assembling the torque spring set......................................................................................... 100
24.3 Single spring type ................................................................................................................ 101
24.4 Inspection............................................................................................................................. 102
24.5 Removal and installation...................................................................................................... 103
COOLING SYSTEM
25 GENERAL.................................................................................................................................. 106
25.1 Specifications....................................................................................................................... 106
25.2 Disassembly......................................................................................................................... 107
26 FAN AND FAN BELT............................................................................................................. 108
26.1 Fan belt inspection............................................................................................................... 108
26.2 Fan inspection...................................................................................................................... 108
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27 WATER PUMP ......................................................................................................................... 109
27.1 Removal and installation...................................................................................................... 109
27.2 Inspection............................................................................................................................. 109
28 THERMOSTAT......................................................................................................................... 110
28.1 Removal and installation...................................................................................................... 110
28.2 Inspection............................................................................................................................. 110
29 WATER TEMPERATURE GAGE UNIT AND THERMOSWITCH.............................. 111
29.1 Inspection of water temperature gage unit........................................................................... 111
29.2 Inspection of thermoswitch .................................................................................................. 111
AIR CLEANER
30 AIR CLEANER ......................................................................................................................... 114
30.1 Disassembly......................................................................................................................... 114
30.2 Inspection............................................................................................................................. 115
ELECTRICAL SYSTEM
31 GENERAL.................................................................................................................................. 118
31.1 Specifications....................................................................................................................... 118
31.2 Wiring diagrams ................................................................................................................... 120
32 STARTER .................................................................................................................................. 122
32.1 Structure .............................................................................................................................. 122
32.2 Inspection (assembly) .......................................................................................................... 123
32.3 Disassembly......................................................................................................................... 125
32.4 Inspection............................................................................................................................. 126
32.5 Assembly and adjustment.................................................................................................... 128
33 ALTERNATOR AND DYNAMO........................................................................................... 129
33.1 Structure .............................................................................................................................. 129
33.2 Dynamo................................................................................................................................ 130
33.3 Inspection of the alternator (installed on the engine) ........................................................... 130
33.4 Output inspection ................................................................................................................. 131
33.5 Removal............................................................................................................................... 131
33.6 Disassembly of alternator .................................................................................................... 131
33.7 Inspection............................................................................................................................. 132
33.8 Installation............................................................................................................................ 135
33.9 Alternator and regulator ....................................................................................................... 135
34 GLOW PLUG ............................................................................................................................ 137
34.1 Removal............................................................................................................................... 137
34.2 Inspection............................................................................................................................. 137
34.3 Installation............................................................................................................................ 137
35 KEY-OFF STOP SYSTEM .................................................................................................... 138
35.1 General ................................................................................................................................ 138
35.2 Control timer unit.................................................................................................................. 138
35.3 Fuel cutoff solenoid (ETS type)............................................................................................ 138
35.4 Fuel cutoff solenoid (ETR type) ........................................................................................... 139
36 GLOW TIMER SYSTEM........................................................................................................ 141
36.1 General ................................................................................................................................ 141
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36.2 Glow timer............................................................................................................................ 141
36.3 Glow relay ............................................................................................................................ 141
SERVICE DATA
37 PERIODIC INSPECTION CHART....................................................................................... 144
37.1 Periodic service chart........................................................................................................... 144
38 SPECIFICATIONS AND MAINTENANCE STANDARDS............................................ 145
38.1 Engine Main Parts................................................................................................................ 145
38.2 Lubrication System .............................................................................................................. 148
38.3 Fuel System ......................................................................................................................... 148
38.4 Governor System ................................................................................................................. 149
38.5 Cooling System.................................................................................................................... 149
38.6 Electrical System ................................................................................................................. 150
39 TIGHTENING TORQUE CHART AND SEALANT CHART......................................... 152
39.1 Tightening Torque for Main Bolts......................................................................................... 152
39.2 Tightening Torque for Common Bolts and Nuts................................................................... 152
39.3 Tightening Torque for Common Plugs ................................................................................. 153
39.4 Sealant Chart ....................................................................................................................... 153
40 SPECIAL TOOLS .................................................................................................................... 154
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GENERAL
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Page 12
ENGINE MODEL AND ENGINE NUMBER GENERAL
GENERAL
1 ENGINE MODEL AND
ENGINE NUMBER
1.1 Model, classification and use
1.1.1 Engine model
Model Application Use
L2A 11,12 - For Agricultural
L2C
L2B 31, 32 - For Industrial
L3A
L3C 61, 62 - For Export only
L3E
Table 1 Engine model and usage
1.1.2 Engine model and application codes
L 3 C – 11 A
L – Name of series (L: Lightweight engine)
3 – Number of cylinders (2: two, 3: three)
C – Cylinder bore
• A: ø65, C: ø70,
• E: ø76
11 – Application
• 11: Agricultural, 31: Industrial,
• 61: For export only
A – Subdivision of specification
t
1.2 Engine model embossment and engine number stamp
1.2.1 Embossment of engine model and
cylinder volume
Figure 1 Engine model and cylinder volume
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The engine model and cylinder volume are embossed
on the side of injection pump mounting portion of the
cylinder block.
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GENERAL
Figure 2 Engine number
ENGINE MODEL AND ENGINE NUMBER
1.2.2 Engine number stamp
The engine number is stamped on the injection pump
mounting portion of the cylinder block (on the upper
side of the tie rod cover). It is a serial number beginning
with 1001 shown as below.
Number Engine model
1001 - (ALL models)
Table 2 Engine number stamp
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EXTERNAL VIEW GENERAL
GENERAL
2 EXTERNAL VIEW
2.1 Engine L2
Engine hangers
Air vent screw
Water pump
Fuel injection pump
Fuel injector
Air inlet cover
Stop solenoid
Fuel filter
Side oil filler
Coolant drain plug
Oil pressure switch
Oil filter
REAR
Thermostat housing
Thermoswitch
Alternator
Fan
V-b elt
Dipstick
Oil drain plug
FRONT
RIGHT SIDE VIEW
Top oil filler
Exhaust manifold
Flywheel housing
Flywheel
Starter
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Crankshaft pulley
Oil pan
FRONT
LEFT SIDE VIEW
ENGLISH
REAR
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GENERAL
EXTERNAL VIEW
2.2 Engine L3
Fuel injector
Air inlet cover
Stop solenoid
Fuel filter
Coolant drain plug
Oil filter
REAR
Engine hangers
Air vent screw
Water pump
Fuel injection pump
Side oil filler
Oil pressure switch
Dipstick
Oil drain plug
FRONT
Thermostat housing
Thermoswitch
Fan
Alternator
V-belt
Crankshaft pulley
Oil pan
RIGHT SIDE VIEW
Top oil filler
Exhaust manifold
Flywheel housing
Flywheel
Starter
FRONT
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LEFT SIDE VIEW
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REAR
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Page 16
FEATURES GENERAL
GENERAL
3FEATURES
3.1 Aim of development
The L-series designs are compact, lightweight engines
suitable for superseding gasoline engines to power
lawn mowers, vehicles, etc. The high-speed (3600 min
1
continuous) engines are also available for generators,
welders, and marine use. The L series are the smallest
and the lightest water-cooled diesel engines in the
world.
3.2 Features of the new series
3.2.1 Small and lightweight engine
The new L-series are 10 to 20% lighter in weight and
15 to 20% smaller in contour volume than the same
class of competitor’s engines.
-
Figure 3 Injection pump
3.2.2 Low noise and economical fuel
consumption
Low noise and economical fuel consumption are
attained by the well designed cylinder block
construction (having curved side faces), the rearranged
combustion chambers, and the compacted fuel
injection system.
3.2.3 Easy starting
The engine can be started instantly only by keeping the
starting switch key in the ON position for about 6
seconds to feed electric current to the glow plugs
automatically (For engines with the automatic glow plug
system). The new governor mechanism also
contributes to easy engine start, by increasing the
amount of fuel injection and delaying injection timing,
without moving the throttle lever to the “full throttle”
position.
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GENERAL
Figure 4 Nozzle holders and return pipe
FEATURES
3.2.4 Multipurpose engine
The L-series engine can be equipped with various
kinds of optional devices.
Ex.
• Key-OFF stop system (Fuel cutoff valve)
• Torque spring
• Manual stop lever
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SPECIFICATIONS GENERAL
GENERAL
4 SPECIFICATIONS
System Item
Type 4-cycle, water-cooled, vertical, overhead valve, diesel engine
Combustion chamber Swirl chamber type
No. of cylinders 2 3
ENGINE
PROPER
LUBRICATING
SYSTEM
Bore x Stroke (mm) 65x70 70x70 76x70 65x70 70x70 76x70
Total displacement (l ) 0.464 0.538 0.635 0.696 0.808 0.952
Compression ratio 23
Firing order 1 - 2 1 - 3 - 2
Dry weight (kg) 61 75
Lubricating method Forced lubrication
Oil pump Gear type
Oil filter Paper element type
Oil capacity:
FULL level/EMPTY level (l )
(Exclusive of oil filter capacity 0.5 l )
1
Model
L2A L2C L2E L3A L3C L3E
2.4/1.4 3.0/1.5 or 3.6/1.8 or 4.8/3.0
Fuel injection pump Bosch type NC
Nozzle Throttle type
FUEL SYSTEM
INTAKE SYSTEM Air cleaner Paper-element type or Oil-bath type
COOLING
SYSTEM
ELECTRICAL
SYSTEM
Fuel injection pressure 140 kgf/cm
Fuel to be used Diesel fuel; see chapter 7
Governor Centrifugal weight type
Cooling method Forced circulation of water
Water pump Centrifugal type
Coolant capacity (l)
(Engine proper only)
Starter (V - kW) Solenoid shift type (12-1.2 or 12-1.6 or 12-1.7)
Alternator (V - A) AC generator (12-40)
Glow plug Sheathed type
Battery
(capacity depends on application)
12V, 45 Ah or more 12V, 60 Ah or more
1.2 1.8
2
(1,991 psi) [13,729 kPa]
Table 3 Specifications
1 All specifications are subject to change without any prior notice.
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GENERAL
Figure 5 Checking oil level
MAINTENANCE
GENERAL
5 MAINTENANCE
5.1 Engine oil and oil filter
5.1.1 Checking and correcting the engine
oil level
Procedure
1. Place the engine horizontally.
2. Check the oil level with the oil level gage. If the oil
level has fallen to the lower limit, add oil up to the
upper limit.
3. Check the oil level before (everyday) operation of
the engine.
CAUTION
a. Whenever oil is added, check the oil level again
after waiting for about 1 minute.
b. When adding oil, use only the same engine oil as
used in the engine.
c. When checking the oil level in an engine which
has not been used for long time, check the oil
level again after running the engine for a few
minutes.
Figure 6 Oil level gage
5.1.2 Oil change intervals
Change the oil and the oil filter after initial 50 service
hour of a new engine and, thereafter, every 100 hours
of operation or once a year (whatever comes first).
Except generator application, 250 hours or once a year
(whatever comes first) can be applied for industrial and
marine application.
5.1.3 Engine oil to be used
Engine oil must conform to the API classification and
viscosity number specified in the table below.
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MAINTENANCE GENERAL
API
classification
Class CF
or CF-4
Atm. temperature Viscosity
Above 20°C [68°F] SAE30
5° to 20°C [41 to
68°F]
Below 5°C [41°F] SAE10W-30
All seasons SAE10W-30
SAE20
Table 4 API classification
5.1.4 Replacing the oil filter
When replacing the oil filter, use only the genuine
replacement filter.
Figure 7 Oil filter
5.1.5 Changing the oil
To change oil, first warm up the engine and remove the
drain plug to let oil drain completely. Put back the drain
plug and refill the oil pan with fresh engine oil through
the oil filler.
Tightening torque N·m (kgf·m) [lbf·ft]
Description Standard
Oil pan drain plug
tightening torque
Table 5 Tightening torque
Oil capacity (Upper
limit/Lower limit)
(excluding 0.5 l of
oil filter capacity)
1 [U.S.gal]
49.0 to 58.8 (5.0 to 6.0)
[36.17 to 43.40]
L2 L3
2.4/1.4
[0.6341/
0.3699]
Ordinary type 3.0/1.5
[0.7926/0.3963]
Deep type 3.6/1.8
[0.9511/0.4756] or
4.8/3.0 [1.2682/
0.7926]
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Table 6 Oil capacity
5.1.6 Replacing the oil filter
Procedure
1. Remove the oil filter with a filter wrench or the like.
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GENERAL
MAINTENANCE
2. Thoroughly clean the filter mounting surface of the
filter bracket. Install the new filter with the O-ring
coated with engine oil and tighten securely by
hand.
Unit: N·m (kgf·m) [lbf·ft]
Tightening torque 10.8 to 12.7 (1.1 to 1.3) [7.96 to 9.40]
Table 7 Tightening torque
CAUTION
Be careful not to twist the O-ring.
3. Run the engine for several minutes and make sure
that no oil leaks.
4. After stopping the engine, check the oil level. If
necessary, add oil.
M10 bolt: 73.5 to 83.4 N·m (7.5 to 8.5 kgf·m)
[54.25 to 61.48 lbf·ft]
M8 bolt: 19.6 to 29.4 N·m (2.0 to 3.0 kgf·m)
[14.47 to 21.70 lbf·ft]
Figure 8 Cylinder head bolt tightening sequence
(L2)
M10 bolt: 73.5 to 83.4 N·m (7.5 to 8.5 kgf·m)
[54.25 to 61.48 lbf·ft]
5.2 Retightening the cylinder head
bolts
When retightening the cylinder head bolts, drain out
coolant, loosen the bolts slightly, and then retighten the
bolts to the specified torque in the numerical order
illustrated at right.
Tightening
torque
M10 bolt 73.5 to 83.4 (7.5 to 8.5)
M8 bolt 19.6 to 29.4 (2.0 to 3.0)
Table 8 Tightening torque
Rocker stay
tightening
torque
M10 bolt 73.5 to 83.4 (7.5 to 8.5)
Unit: N·m (kgf·m) [lbf·ft]
[54.25 to 61.48]
[14.47 to 21.70]
Unit: N·m (kgf·m) [lbf·ft]
[54.25 to 61.48]
M8 bolt: 19.6 to 29.4 N·m (2.0 to 3.0 kgf·m)
[14.47 to 21.70 lbf·ft]
Figure 9 Cylinder head bolt tightening sequence
(L3)
Service Manual Mitsubishi L-Series diesel engines
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Table 9 Rocker stay tightening torque
The rocker assembly (the rocker arms, shaft and stays)
is to be kept removed when the cylinder head bolts are
retightened.
ENGLISH
M8 bolt 19.6 to 29.4 (2.0 to 3.0)
[14.47 to 21.70]
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MAINTENANCE GENERAL
5.3 Adjusting the valve clearance
CAUTION
Be sure to retighten the cylinder head bolts before
adjusting the valve clearance.
Figure 10 Adjusting valve clearance
Procedure
1. Set the cylinder to be adjusted to the top dead
center of compression stroke.
Mark on
gear case
TDC mark on
crankshaft pulley
Figure 11 Timing mark
Tightening
torque
M10 bolt 73.5 to 83.4 (7.5 to 8.5)
M8 bolt 19.6 to 29.4 (2.0 to 3.0)
Table 10 Tightening torque
2. The top dead center of compression stroke can be
obtained by aligning the TDC (Top Dead Center)
mark (notch) on the crankshaft pulley with the
mark on the gear case.
3. First align the TDC mark for the No. 1 cylinder.
Confirm that the valves do not move up and down
when the crankshaft is turned about 20° in normal
direction of rotation and in reverse direction.
4. When setting the top dead center for the No. 2
cylinder and that for the No. 3 cylinder, perform as
follows:
a L2 (Two-cylinder engine)
Turn the crankshaft 180° clockwise from TDC
(Top Dead Center) of the No. 1 cylinder, to set
the No. 2 cylinder TDC.
b L3 (Three-cylinder engine)
Turn the crankshaft 240° clockwise from TDC
of the No. 2 cylinder, to set the No. 3 cylinder
TDC. Further, turn the crankshaft 240°
clockwise from No. 3 cylinder TDC and
reconfirm the position of the No. 2 cylinder
TDC.
Unit: N·m (kgf·m) [lbf·ft]
[54.25 to 61.48]
[14.47 to 21.70]
22 / 155
ENGLISH
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 23
GENERAL
Approx: 10 mm
[0.3937 in.]
(98 N (10 kgf) [22 lbf]
of thumb force)
Figure 12 Adjusting fan belt tension
Figure 13 Fuel filter air bleeding
MAINTENANCE
5.4 Adjusting the fan belt tension
To check if the belt tension is appropriate, press the
belt at a midpoint between the alternator pulley and
crankshaft pulley with your thumb, and check that the
amount of belt deflection is about 10 mm [0.3937 in.]
(about 98 N (10 kgf) [22 lbf]).
5.5 Bleeding air from the fuel system
Procedure
1. Loosen the air vent screw on the fuel filter.
2. For engine without feed pump, fuel flows down and
enters the fuel filter, wait for fuel to overflow from
the air vent screw. Then tighten the air vent screw.
3. For engine with the electromagnetic fuel pump,
turn the starting switch key to the ON position to
feed fuel to the fuel filter. Loosen the air vent screw
on the filter and, after bleeding air, tighten the air
vent screw.
4. Loosen the air vent screw on the fuel injection
pump to let air bleed from the fuel pipe and fuel
injection pump.
5. Air in the injection pipes and nozzles is driven out
automatically by cranking the engine.
Figure 14 Fuel injection pump air bleeding
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
23 / 155
Page 24
MAINTENANCE GENERAL
5.6 Replacing the fuel filter
5.6.1 Cartridge type
Replace the cartridge type filter as an assembly if
accumulation of dust or water is in its element. Regular
replacement interval is every 500 service hours of
engine operation. Check the filter every 100 service
hours and, if necessary, replace early.
5.6.2 Separate type filter with cock
Close the filter cock, remove the ring nut, and take out
Figure 15 Cartridge type filter
the element from the inside of filter. Clean or replace
the element.
5.6.3 Fuel pump
The following three types of fuel pumps are available.
Which type of pump is to be used for an engine
depends upon engine specification.
Filter
Magnet
Cover
Figure 16 Plunger type (common) fuel pump
1. Plunger type electromagnetic pump
The plunger-type pumps are classified as the common, large-sized pump having a filter element or
as the compact lightweight, low-priced pump without filter element. Regardless of classification,
check the plunger-type pump for normal function
and make sure that it does not leak fuel. Only on
the pump with filter element, remove the cover and
clean or replace the filter element.
Figure 17 Plunger type (compact) fuel pump
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ENGLISH
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 25
GENERAL
Figure 18 Diaphragm type fuel pump
Adapter
Camshaft, fuel
injection pump
Fuel pump
Primer lever
MAINTENANCE
2. Diaphragm type electromagnetic pump
The diaphragm type electromagnetic pump should
not be disassembled. Like the compact plungertype pump mentioned above, check the pump for
functions and fuel leak.
3. Mechanical type fuel pump
This type of fuel pump is installed with an adapter
on the rear-end side of the fuel injection pump
camshaft. As the camshaft rotates, the fuel pump
cam pushes the tappet to actuate the diaphragm of
the fuel pump. This type of fuel pump is provided
with a priming lever to allow manual feed to fuel.
Check the fuel pump for normal function and make
sure that it does not leak fuel or make unusual
noise.
Pump type Delivery flow
Shut-off
pressure
Figure 19 Mechanical type fuel pump
Plunger type
(common)
Plunger type
(compact)
Diaphragm
type
Mechanical
type
0.9 l
[0.24 U.S.gal]/ min
or more
0.4 l
[0.11 U.S.gal]/ min
or more
0.37 l
[0.10 U.S.gal]/ min
or more
0.255 l
[0.06 U.S.gal]/ min
or more
0.03 MPa
(0.35 kgf/cm2)
[4.98 psi]
0.03 MPa
(0.35 kgf/cm
[4.98 psi]
0.01 MPa
(0.15 kgf/cm
[2.13 psi]
0.01 MPa
(0.15 kgf/cm
[2.13 psi]
2
)
2
)
2
)
Table 11 Fuel pumps at 12V (electromagnetic
pumps only) and at 20°C [68°F]
5.6.4 Draining water from the water
sedimentator
For engine provided with a water sedimentator, remove
the filter ring nut involved and take out the cup. Wipe off
water and dust accumulated in the cup.
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
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Page 26
MAINTENANCE GENERAL
5.7 Checking and adjusting injection timing
To check and adjust injection timing, use the following
procedure:
1. Disconnect the No. 1 injection pipe.
2. Remove the No. 1 delivery valve from the injection
pump. Put back the valve holder only.
CAUTION
Figure 20 Removing delivery valve
Be sure to shut off the fuel feed before removing the
delivery valve.
3. Remove the tie-rod cover and disconnect the tie-
rod from the control rack.
4. Set the control rack to a midway position in the
working range.
5. Open the fuel feed pipe and make sure that fuel
flows from the delivery valve holder.
6. Turn the crankshaft in the direction of normal
rotation (clockwise) and find an instant that fuel
stops flowing from the delivery valve holder. This
instant is the real injection timing.
Mark on gear
case
IT mark on
pulley
Figure 21 Injection timing mark
Figure 22 Adjusting shim thickness
TDC mark
CAUTION
The standard injection timing differs with engine
specification and engine speed.
Check to see whether the real injection timing
coincides with the standard injection timing (whether
the IT mark on the crankshaft pulley aligns with the
mark on the gear case).
7. If they do not coincide with each other, adjust
thickness of the injection pump mounting shim.
Increasing or decreasing shim thickness by 0.1
mm [0.0039 in.] causes the real injection timing to
vary about 1°.
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Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 27
GENERAL
Figure 23 Removing injection pump
MAINTENANCE
8. To remove the injection pump, first disconnect the
injection pipes and fuel feed pipe from the injection
pump. Then, remove the tie-rod cover and tie-rod.
Dismount the pump assembly. Reassembly
sequence of the pump is the reverse of
disassembly.
9. In the dusty place or when the engine is dirty,
removal of a delivery valve may cause dust to
enter into the injection pump. Under such
circumstances leave the delivery valve installed
and check injection timing using the following
procedure:
a Remove the tie-rod cover and disconnect the
tie-rod from the control rack.
b Set the control rack to a midway position in
the working range. Disconnect the injection
pipe from the No. 1 nozzle. Turn the
crankshaft gradually in the direction of normal
rotation until swelling of fuel is found at the
open end of the injection pipe. This instant is
the real injection timing, which will come
approx. 1° later than standard injection timing.
LOW-SPEED
set bolt
HIGH-SPEED
set bolt
Figure 24 HIGH-SPEED and LOW-SPEED set bolts
1
min-
Less than 2000 BTDC 15° BTDC 15°
200 to less than
3600
3600 or more BTDC 19° BTDC 19°
Table 12 Standard injection timing
Model L2 Model L3
BTDC 17° BTDC 17°
5.8 Adjusting the engine speeds
To adjust engine speed, remove the cooling fan and
install the safety cover over the fan to reduce the risk of
injury.
1. The upper limit of engine speed can be adjusted
with the HIGH-SPEED stopper bolt. This stopper
bolt has been set properly and sealed in the
factory before shipping of the engine. Never
attempt to open the seal unless it is necessary.
2. The lower limit of engine speed can be adjusted
with the LOW-SPEED stopper bolt.
3. Never remove the sealing cap unless it is
necessary to adjust the torque spring set.
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
CAUTION
Warm up the engine (until coolant temperature rises
up to 60°C [140°F] or above) before adjusting engine
speeds.
4. During running of the engine for speed adjustment,
ENGLISH
check the engine for gas leak, water leak, oil leak
and fuel leak.
27 / 155
Page 28
MAINTENANCE GENERAL
5. After adjustment, perform engine acceleration and
deceleration test to confirm that the engine is free
from hunting and smoking.
5.9 Checking and adjustment of nozzles
To check and adjust the injection nozzles, use the
following procedure:
5.9.1 Injection start pressure
1. Remove the nozzle assembly to be tested from the
cylinder head and set the nozzle on the nozzle
tester.
Perform air bleeding by moving the tester handle
up and down.
Figure 25 Testing injection start pressure
2. Operate the handle at a rate of one discharge a
second or more and read the gage pressure of fuel
injected from the nozzle.
H25 to 29 N m
(2.5 to 3.0 kgf m)
[18.08 to 21.70 lbf ft]
Figure 26 Installing nozzle assembly
Injection start pressure 13.7 MPa
+1.0
- 0
+10
(140 kgf/cm
- 0
+142
[1992 psi]
- 0
2
)
Table 13 Start pressure
3. If reading of gage pressure exceeds the specified
range, disassemble the nozzle and adjust by using
the adjusting shim.
Increasing or decreasing shim thickness by 0.1
mm [0.0039 in.] will cause injection pressure to
vary about 0.98 MPa (10 kgf/cm2) [142 psi].
4. When reassembling the nozzle, use the following
values of tightening torque:
Nozzle Tightening torque
Nozzle tightening (to
cylinder head) torque
Nozzle retaining nut
tightening torque
Nozzle union collar
tightening torque
49.0 to 58.8 N·m
(5.0 to 6.0 kgf·m )
[36.17 to 43.40 lbf·ft]
34.3 to 39.2 N·m
(3.5 to 4.0 kgf·m)
[25.32 to 28.93 lbf·ft]
25 to29 N·m
(2.5 to 3.0 kgf·m)
[18.08 to 21.70 lbf·ft]
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ENGLISH
Table 14 Tightening torque
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 29
GENERAL
MAINTENANCE
5.9.2 Chattering test
Operate the tester handle at a speed of about one
stroke per second.
1. Needle valve oscillation
If the fuel spray shows good atomization, making
intermittent sounds, and oscillations of the needle
valve are transmitted to the handle, then the nozzle is considered as normal.
Good
Bad
Figure 27 Chattering test
Good
Bad
Figure 28 After-spilling
Bad
Bad
2. Shape of fuel spray
The nozzle should inject fuel spray straight in the
direction of its axis. A nozzle is defective if it does
not inject steadily or it injects fuel in several separate stripes.
A nozzle is defective if it spills fuel accumulated on
the bottom of the nozzle after chattering test. However, a very small drop of fuel remaining on the tip
of nozzle after chattering test may be regarded as
normal.
5.9.3 Injection Test
1. Operate the tester handle at a speed of 4 to 6
strokes per second.
2. A nozzle should inject fuel spray uniformly in the
shape of a cone.
5.9.4 Checking the compression pressure
Make sure of the following:
1. The engine oil level, air cleaner, starting motor, and
battery are well-conditioned.
Figure 29 Testing compression pressure
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
2. Warm up the engine to the coolant temperature of
Measure the compression pressure using the following
procedure:
1. The following are the conditions to perform test.
2. Pull the stop lever to the “non-injection” position.
3. Remove the glow plug from the cylinder to be
ENGLISH
Engine speed 250 to 280 min
Compression
pressure
Pressure difference
between cylinders
2.84 to 3.14 Mpa
(29 to 32 kgf/cm2)
[413 to 455 psi]
0.29 MPa (3 kgf/cm
[43 psi] or less
-1
2
)
Table 15 Conditions to perform test
50°C [122°F] or more.
tested. Set the compression gage adapter to that
cylinder and install the gage.
29 / 155
Page 30
MAINTENANCE GENERAL
Special tool name Part No.
Compression gage
adapter
ST332270
Table 16 Tools
4. Crank the engine with the starting motor until a
stable reading of the compression gage is
obtained.
5. After reading the gage, remove the compression
gage and adapter. Put back the glow plug.
6. Check all cylinders using the same procedure
described above.
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Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 31
GENERAL
TROUBLESHOOTING
GENERAL
6 TROUBLESHOOTING
6.1 Hints on using the trouble-
diagnosis chart
1. As for diesel engines, trouble symptoms and
causes are often so complicated that it will be
difficult to locate the root cause by judging from a
trouble symptom.
2. For example, trouble symptoms caused by the
faulty injection pump, faulty injection nozzles and
improper cylinder compression, make the same
kind of phenomenon. When judging the cause of
trouble from examination, be careful to make
conclusion because it can be very complicated.
3. The trouble-diagnosis charts on the following
pages are prepared in such a way of beginning
with the most possible or easiest-to-inspect item
and then proceeding stepwise to less possible or
more complicated items.
4. Before troubleshooting, you should have a right
understanding of the following features about the
structure and fuel combustion in the diesel
engines.
a Normal engine operation is accompanied by
combustion noise (diesel knocking sound).
b A heavy-loaded engine exhausts some black
smoke.
c When operated, an engine may cause
vibration because of high cylinder
compression and large output torque.
d When an engine is accelerated or decelerated
quickly, some hunting may occur.
CAUTION
a. Do not attempt to readjust or disassemble the
injection pump for the purpose of
troubleshooting, without use of a pump tester,
which is indispensable to measure injection
quantity for each cylinder.
b. To check if state of combustion in a cylinder is
normal or not, loosen the injection pipe to cut fuel
feed to that cylinder, and check the slowdown
speed of the engine. Compare the degree of
slowdown with the other cylinders.
Service Manual Mitsubishi L-Series diesel engines
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ENGLISH
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TROUBLESHOOTING GENERAL
6.2 Hard starting
6.2.1 Matters to be checked before
diagnosis
1. Clogging of the air cleaner
2. Coagulation of engine oil
3. Use of poor-quality fuel
4. Lowering of cranking speed
6.2.2 Diagnosis
Does preheating system
operate properly?
V Yes Yes Z Inspect glow plug.
Is electric wiring normal?
Does fuel feed pump, if provided operate when key switch is turned ON?
V Yes
Does fuel flow in fuel line? No Z
V Yes
Is engine in good order?
(Injection timing and valve timing)
V Yes
Do injection nozzles operate properly?
State of fuel spray and injection starting pressure.
V Yes
No Z
Does current flow in glow plug
circuit as soon as key switch is
turned to ‘H’ (ON)?
V
Does fuel flow out when fuel
injection pump air vent screw is
loosened?
No Z
No Z
No Z
No Z Adjust engine properly.
No Z Inspect injection nozzles.
Inspect key switch, wiring and
glow indicator.
Inspect fuel pump and/or
wiring.
Inspect fuel filter, fuel pipe and
fuel tank.
V Yes
Inspect injection pump.
32 / 155
Is cylinder compression pressure proper? No Z
ENGLISH
Service Manual Mitsubishi L-Series diesel engines
Inspect valves, pistons, piston
rings and cylinder head
gasket.
Version 08/2004
Page 33
GENERAL
6.3 Knocking
Diesel engines are usually accompanied by fuel
combustion noise (diesel knocking sounds) because of
its inherent mechanism.
A trouble should be suspected only when the engine
makes abnormally large sounds.
6.3.1 Matters to be checked before
1. Clogging of the air cleaner
2. Use of poor-quality fuel (Low cetane number fuel
6.3.2 Diagnosis
Is injection timing correct? No Z Adjust injection timing.
V Yes
Do injection nozzles operate properly?
(Check for lowering of injection start pressure and improper shape of fuel
spray.)
TROUBLESHOOTING
diagnosis
such as used for burner)
No Z Inspect injection nozzles.
V Yes
Is cylinder compression proper? No Z
V Yes
Does injection pump operate properly?
(Check for uniformity of injection quantity.)
V Yes
Mechanical noise
(Worn or damaged main
moving parts)
Inspect valves, pistons, piston
rings and cylinder head
gasket.
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
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Page 34
TROUBLESHOOTING GENERAL
6.4 Overheating
6.4.1 Matters to be checked before
diagnosis
1. Lack of coolant and leakage
2. Loosening of fan belt
3. Clogging of radiator fins
4. Wrong concentration of antifreeze solution
5. Clogging of muffler
6. Lack of engine oil and deterioration
7. Lack of cooling air
8. Defective thermostat
6.4.2 Diagnosis
Is engine operating condition too heavy?
(Check for overload continuous running.)
V Yes
Is cooling system in good order?
(Check cylinder head gasket for leaking, water pump, water hose and radiator
fins for clogging and thermostat for malfunctioning.)
V Yes
Is injection timing correct? No Z Adjust injection timing.
CAUTION
Overheating is mostly caused by mis-matching load
to the engine. If overheating arises only when the
engine drives a load, measure the ambient
temperature and coolant temperature under the
working load condition (with full open thermostat) to
see if the rise of the temperature is 60°C or lower
than ambient temperature. If it exceeds, it is
recommended to check other factors than engine
main parts.
No Z Find the cause over overload.
No Z Repair cooling system.
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Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 35
GENERAL
V Yes
TROUBLESHOOTING
6.5 Black-smoky exhaust
6.5.1 Matters to be checked before
diagnosis
1. Clogging of air cleaner element
2. Use of poor-quality fuel
3. Overload
6.5.2 Diagnosis
Is smoke set of injection pump correct? No Z Adjust smoke set.
Is engine adjusted properly?
(Check for excessive valve clearance and improper injection timing.)
V Yes
Do injection nozzles operate properly?
(Check for improper shape of fuel spray and for excessively high injection
starting pressure.)
V Yes
Is cylinder compression proper? No Z
V Yes
Inspect injection pump.
No Z Adjust engine.
No Z Inspect injection nozzles.
Inspect valves, cylinder head
gasket, pistons, and piston
rings.
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
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Page 36
TROUBLESHOOTING GENERAL
6.6 Unsteady idling
6.6.1 Matters to be checked before
diagnosis
1. Faulty engine control system
2. Too high viscosity of engine oil
3. Use of poor-quality fuel
6.6.2 Diagnosis
Is engine adjusted properly?
(Check for idling speed, valve clearance, and injection timing.)
V Yes
Do injection nozzles operate properly?
(Check for shape of fuel spray and injection starting pressure.)
V Yes
Is cylinder compression pressure proper?
(Check equality between cylinders.)
V Yes
Inspect injection pump and
governor system.
No Z Adjust engine.
No Z Inspect injection nozzles.
No Z
Inspect valves, pistons and
piston rings.
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Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 37
GENERAL
Is sufficient fuel flow in fuel
line?
No Z
6.7 Low output
6.7.1 Matters to be checked before
diagnosis
1. Seizing of engine moving parts
2. Too high engine oil viscosity
3. Use of poor-quality fuel
4. Clogging of air cleaner element
5. Clogging of muffler
6. Malfunctioning of drive system
6.7.2 Diagnosis
Engine without fuel feed pump:
Is gravitational flow of fuel
normal?
Engine with electromagnetic
fuel feed pump:
Does fuel pump feed fuel with
key switch placed in ON?
TROUBLESHOOTING
No Z
Inspect fuel filter, fuel pipe and
fuel tank.
V
V Yes Yes Z Inspect fuel pump.
Is engine adjusted properly?
(Check for valve clearance and injection timing.)
V Yes
Do injection nozzles operate properly?
(Check for condition of fuel mist injection and injection starting pressure.)
V Yes
Is cylinder compression proper? No Z
V Yes
Inspect injection pump.
No Z Adjust engine.
No Z Inspect injection nozzles.
Inspect valves, cylinder head
gasket, pistons and piston
rings.
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
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TROUBLESHOOTING GENERAL
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ENGLISH
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 39
ENGINE MAIN PARTS
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
39 / 155
Page 40
GENERAL ENGINE MAIN PARTS
ENGINE MAIN PARTS
7 GENERAL
7.1 Specifications
Model
Item
L2 L3
Material Special cast iron
CYLINDER
HEAD
VALVE
SEATS
VALVES
VALVE
SPRINGS
CYLINDER
HEAD GASKET
CYLINDER
HEAD BOLTS
CAMSHAFT
Combustion chamber type Swirl chamber
Material of chamber Heat-resisting steel (press-fitted in cylinder head)
Type of intake and exhaust ports Cross-flow type
-1
Material
Heat-resisting steel (3600 min
Special cast iron (3000 min
Face angle 45°
Identification mark inlet IN
Identification mark exhaust EX
Type Uniformly pitched, single
Identification mark White paint atop (common to inlet and exhaust valves)
Material Carbon sheet (Graphoil)
Material Special steel
M10 x 6 M10 x 8
Size x number bolts
M8 x 2 M8 x 3
Material valve cam
Carbon steel
Material pump cam
specification engines)
-1
or less engines)
Arrangement – drive Side – gear driven
Cylinder bore mm [in.]
CYLINDER
BLOCK
CRANKSHAFT
PISTON
Cylinder liner type Monoblock type
Water jacket type A, C: Full jacket, E: “Siamese” type
Material Carbon Steel
Surface treatment Hardening (Induction)
Main journal dia. x Crankpin dia.
mm [in.]
Type “Autothermic”
Joint to connecting rod Semi-floating
Cooling Oil jet
Table 17 Specifications
40 / 155
[2.5591]
ENGLISH
L2A L2C L2E L3A L3C L3E
65
70
[2.7559]
76
[2.9921]
43 x 40 [1.6929 x 1.5748]
Service Manual Mitsubishi L-Series diesel engines
65
[2.5591]
70
[2.7559]
76
[2.9921]
Version 08/2004
Page 41
ENGINE MAIN PARTS
Item
No. 1 Semi-keystone type
GENERAL
Model
L2 L3
PISTON RINGS
OIL PUMP
TIMING GEARS
No. 2 Plain type
Oil ring With coil expander
Type Gear type
Drive Direct drive by crankshaft
Crankshaft gear Number of teeth: 26
Idle gear Number of teeth: 40
Injection pump camshaft gear Number of teeth: 52
Valve camshaft gear Number of teeth: 52
Table 17 Specifications
7.2 Special Tools
Tool name Part No. Shape Use
Piston pin setting tool For L2A, L3A:
30L91-00030
For L2C, L3C:
30L91-00020
Tool No.
Removal and installation of
piston pin
For L2E, L3E:
30L91-10010
Compression gage adapter ST332270 Measurement of cylinder
compression
Piston ring pliers 31391-12900 Removing and installing
piston ring
Table 18 Special tools
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
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Page 42
ROCKER ARMS AND ROCKER SHAFT ENGINE MAIN PARTS
ENGINE MAIN PARTS
8 ROCKER ARMS AND
ROCKER SHAFT
8.1 Disassembly
2
1
3
4
5
2
3
4
6
6
5
8
7
L2
Figure 30 Rocker system components parts
9
8
7
9
L3
Disassembly sequence
1. Oil filter cap
2. Breather hose
3. Rocker cover
4. Rocker cover gasket
5. Rocker shaft
6. Rocker spring
7. Adjust screw
8. Rocker arm
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ENGLISH
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 43
ENGINE MAIN PARTS
ROCKER ARMS AND ROCKER SHAFT
Front identification
mark (on the valve
side) ø3 [0.12 in.]
hole 1 mm [0.04 in.]
deep
Rocker cover nut tightening
torque: 4.9 to 6.9 N·m (0.5 to
0.7 kgf·m) [3.62 to 5.06 lbf·ft]
Stay tightening torque:
14.7 to 21.6N·m
(1.5 to 2.2 kgf·m)
[10.85 to 15.91 lbf·ft]
8.2 Removal and installation
CAUTION
a. Be careful not to confuse proper direction of
installation of the rocker shaft.
b. After installing the rocker shaft, adjust valve
clearance.
Figure 31 Installing rocker shaft and rocker cover
Figure 32 Inspecting rocker shaft and rocker arms
8.3 Inspection
Check the rocker shaft and rocker arms. If any
defective parts are found, replace them.
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
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Page 44
CYLINDER HEAD ENGINE MAIN PARTS
ENGINE MAIN PARTS
9 CYLINDER HEAD
9.1 Disassembly
Cylinder head cross section
Figure 33 Cylinder head component parts
44 / 155
ENGLISH
Disassembly sequence
1. Cylinder head
2. Valve guide
3. Cylinder head bolt (main bolt)
4. Cylinder head bolt (sub-bolt)
5. Seat ring (3600 min
6. Water outlet fitting
7. Cylinder head gasket
8. Mouth piece
9. Thermostat
10. Thermostat fitting
Service Manual Mitsubishi L-Series diesel engines
-1
specification engine)
Version 08/2004
Page 45
ENGINE MAIN PARTS
Figure 34 Sequence for loosening cylinder head
bolts (L2)
Figure 35 Sequence for loosening cylinder head
bolts (L3)
CYLINDER HEAD
9.2 Removal
1. Remove the injection pipe assembly.
CAUTION
a. When disconnecting each injection pipe from the
delivery valve holder of the injection pump, hold
the holder with a wrench to prevent from
loosening.
b. After removing the pipe assembly, place a cap to
the nozzle holders and delivery valve holders to
prevent from entering the dust.
2. Disconnect the glow plug lead wire.
3. Loosen the alternator bracket bolts and dismount
the alternator.
4. Disconnect the air breather hose.
5. Remove the rocker cover.
6. Remove the rocker shaft assembly.
7. Loosen the cylinder head mounting bolts in the
numerical order illustrated at right and remove the
cylinder head assembly (including the inlet and
exhaust manifolds).
8. Remove the cylinder head gasket.
9. Clean the cylinder head and the cylinder block
surface from which the gasket has been removed.
10. Remove the nozzle holder assemblies and glow
plugs from the cylinder head.
Figure 36 Removing valves
11. Remove the inlet manifold and exhaust manifold
from the cylinder head.
CAUTION
a. When disconnecting each injection pipe from the
delivery valve holder of the injection pump, hold
the holder with a wrench to prevent from
loosening.
b. After removing the pipe assembly, place a cap to
the nozzle holders and delivery valve holders to
prevent from entering the dust.
12. Remove the valve stem seals.
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
45 / 155
Page 46
CYLINDER HEAD ENGINE MAIN PARTS
9.3 Inspection and Repair
Check cylinder head surface for
a warpage between bolt holes:
Check guide for wear and damage
within 0.05 mm [0.0020 in.]
Check for valve contact, wear,
damage, and sink of seat face.
Figure 37 Inspection of cylinder head
14±0.5 mm
[0.5512 ±0.0197 in.]
Figure 38 Press-fitting valve guide
Check for cracks, damage, water
leak and remove oil, sludge, sealant
deposit, carbon deposit.
9.4 Replacement of valve guide
If a valve guide is defective, replace it.
9.4.1 Removal
Press the guide at its upper end and push it out to the
valve seat side.
9.4.2 Installation (press-fitting)
Press-fit the guide from the upper side of the cylinder
head to a height of 14 ±0.5 mm [0.5512 ±0.0197 in.]
from the valve spring seat face.
46 / 155
ENGLISH
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 47
ENGINE MAIN PARTS
CYLINDER HEAD
Valve sinkage
Seat contact and wear
Figure 39 Checking valve sinkage
Width of valve contact:
1.3 to 1.8 mm
[0.0512 to 0.0709 in.]
9.5 Repair of valve seat
If a valve seat is found defective, reface or replace it.
Sinkage of valve
Standard Service limit
0.5 mm [0.0197 in.] 1.5 mm [0.0591 in.]
Table 19 Sinkage of valve
CAUTION
a. When checking valve sinkage, the valve guide
must be in the normal condition.
b. Resurface the valve seat so that it contacts the
mid-portion of the valve face.
Figure 40 Refacing valve seat (Both inlet and
exhaust valves)
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
47 / 155
Page 48
CYLINDER HEAD ENGINE MAIN PARTS
9.6 Installation
Installation sequence of the cylinder head is reverse
order of removal. Pay attention to the following:
1. Renew the cylinder head gasket. Any sealant is
not necessary. The engine model is printed on the
upper front of the gasket. Be careful not to confuse
with a gasket for other engine model.
2. Tighten the cylinder head bolts in the numerical
order shown in the figure at right. Tighten each bolt
a little two or three times in total until all are
tightened to the specified torque.
Figure 41 Sequence for tightening cylinder head
bolts (L2)
3. When connecting the injection pipe assembly,
loosen the pipe clamp first.
When tightening the nut at each end of pipe, hold
the nozzle holder or delivery valve holder with a
wrench to prevent from being turned together with
the nut.
Also, be careful not to allow dust to enter the fuel
line.
Figure 42 Sequence for tightening cylinder head
bolts (L3)
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ENGLISH
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 49
ENGINE MAIN PARTS
VALVES AND VALVE SPRINGS
ENGINE MAIN PARTS
10 VALVES AND VALVE
SPRINGS
10.1 Disassembly
(Not installed to
agricultural model)
Figure 43 Valve system component parts
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Disassembly sequence
1. Valve stem cap
2. Valve lock
3. Valve spring retainer
4. Valve stem seal
5. Valve spring
6. Valve
ENGLISH
49 / 155
Page 50
VALVES AND VALVE SPRINGS ENGINE MAIN PARTS
10.2 Removal
1. Dismount the cylinder head assembly.
2. Press the valve spring retainer (to compress the
valve spring) and remove the valve lock.
3. Remove the valve and place it cylinder by cylinder.
Figure 44 Removing valve and valve spring
10.3 Inspection and repair
Wear and
damage
(Not installed
to agricultural
model)
Check the removed parts. If any parts are found
defective, repair or replace them.
Valve fatigue and damage
Fatigue and
damage
Dents and
wear
Ridge and
damage
Margin
Figure 45 Inspection of valve and valve spring
Inspection item Standard Service limit
Free length
(61SG, 63SG)
(Others)
mm [in.]
Set force/Set
length
(61SG, 63SG)
(Others)
N (kgf) [lbf]/
mm [in.]
Perpendicularity 2° 3°
Margin mm [in.] 1.0
40.5 [1.5945]
40.0 [1.5748]
58 (5.94) [13.1]/
35.5 [1.3976]
146 (14.84) [32.7]/
28 [1.1024]
68 (6.89) [15.2]/
35.5 [1.3976]
180 (18.36) [40.5]/
28 [1.1024]
[0.0394]
-1
[-0.0394]
-15%
0.5
[0.0197]
Table 20 Valve inspection and repair
Figure 46 Valve spring tester
50 / 155
ENGLISH
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 51
ENGINE MAIN PARTS
VALVES AND VALVE SPRINGS
10.3.1 Repair of valve face
If the valve face is found worn, resurface with a valve
refacer. If margin of the resurface valve is less than the
service limit, replace the valve.
Figure 47 Inspecting valve
Press this surface
ø14.8 mm [0.5827 in.]
Margin
10.3.2 Repair of valve stem end
If the valve stem end is indented by wear, flatten with
an oil stone.
10.4 Installation
1. Reassemble the valves and valve springs,
referring to the illustrations shown below.
2. Mount the cylinder head assembly.
3. Adjust the valve clearances.
Press the retainer and push the
spring to install retainer lock.
Driving in stem seal
Figure 48 Installation of valve spring
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Installing spring
CAUTION
Be careful not to damage the spring and stem seal by
excessively pushing the spring when installing the
valve spring.
ENGLISH
Installing spring retainer
51 / 155
Page 52
INLET MANIFOLD AND EXHAUST MANIFOLD ENGINE MAIN PARTS
ENGINE MAIN PARTS
11 INLET MANIFOLD AND
EXHAUST MANIFOLD
11.1 Disassembly
2
1
2
Tightening torque:
7.85 to 9.80 N²m
(0.8 to 1.0 kgf²m)
[5.79 to 7.23 lbf²ft]
L3
4
L2
4
5
5
3
L3
3
L2
Tightening torque:
14.7 to 21.6 N·m
(1.5 to 2.2 kgf·m)
[10.85 to 15.91 lbf·ft]
Figure 49 Manifold component parts
52 / 155
ENGLISH
Disassembly sequence
1. Inlet pipe
2. Inlet manifold
3. Exhaust manifold
4. Inlet manifold gasket
5. Exhaust manifold gasket
11.2 Inspection
Check the following matters. If any defect is found,
repair or replace the manifold.
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 53
ENGINE MAIN PARTS
INLET MANIFOLD AND EXHAUST
MANIFOLD
1. Check the mounting surfaces to the cylinder head
for flatness. The surfaces must be flat within 0.15
mm [0.0059 in.].
2. Check the manifolds for corrosion, damage and
cracks.
CAUTION
a. Check the interior of the inlet manifold for dust
and dirt.
b. If any dust is found, check the joints of the air
cleaner and inlet pipe for sealed condition.
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
53 / 155
Page 54
GEAR CASE AND OIL PUMP ENGINE MAIN PARTS
ENGINE MAIN PARTS
12 GEAR CASE AND OIL
PUMP
12.1 Disassembly
Common to L2 and L3
Figure 50 Gear case component parts
54 / 155
ENGLISH
Disassembly sequence
1. Bushings
2. Plug
3. Gear case
4. Front oil seal
5. Relief plunger
6. Relief spring
7. Oil pump inner gear
8. Oil pump outer gear
9. Oil pump housing
10. Gear case gasket
11. High-pressure pump gear housing
12. Housing gasket
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 55
ENGINE MAIN PARTS
GEAR CASE AND OIL PUMP
12.2 Removal
1. Remove the crankshaft pulley.
2. Remove the fan and fan belt.
3. Remove the tie-rod cover from the side face of the
injection pump.
4. Remove the tie-rod and tie-rod spring. Be careful
not to let the spring drop to inside of the case.
5. Remove the governor cover assembly.
6. Remove the water pump assembly.
7. Remove the alternator.
8. Remove the pump housing.
9. Remove the gear case assembly.
12.3 Inspection
Check the removed parts. If any parts are found
defective, repair and replace them.
Cracks and damage
Wear and damage
Spring fatigue
Smooth movement
Seal surface
interference
Figure 51 Inspection of gear case and oil pump
Description
Discharge
Wear, damage and clearance
Thoroughly clean oil line.
Speed, min
Pressure
MPa
(kgf/cm2) [psi]
Flow rate
l [U.S.gal]/min
-1
1000 4000
0.15
(1.5)
[21]
3 [0.79]
more
or
0.20
(2.0)
[28]
8 [4.76]
or
more
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Table 21 Oil pump performance, oil used: SAE30,
ENGLISH
100±5°C [212±9°F]
55 / 155
Page 56
GEAR CASE AND OIL PUMP ENGINE MAIN PARTS
Description
Relief
valve
Speed, min
Opening pressure
MPa
(kgf/cm2) [psi]
Closing pressure
MPa
(kgf/cm2)[psi]
-1
1000 4000
0.29
(3.0)
[43]
—
—
0.49
(5) [71]
or
below
Table 21 Oil pump performance, oil used: SAE30,
100±5°C [212±9°F]
12.4 Replacement of front oil seal
1. Remove the front oil seal.
2. Press-fit the new front oil seal.
CAUTION
Apply thin coat of engine oil to the periphery and lip of
the oil seal
Bushings
+0.20
(41 mm)
0
[1.6142 in.]
To be flush with
this place
+0.0079
0
To be in contact
with bottom
Figure 52 Press-fitting governor shaft bushing
12.5 Replacement of governor shaft
bushings
1. Remove the expansion plug and draw the
bushings out.
2. Press-fit the new bushings into the positions
shown at right.
56 / 155
ENGLISH
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 57
ENGINE MAIN PARTS
GEAR CASE AND OIL PUMP
12.6 Inspection of governor system
Check springs
for fatigue.
Check shaft
for flaws.
Check sliding
sleeve joint for
wear and damage.
Figure 53 Check governor system
Expansion
plug
Grooved pin
A
Protrusion
approx. 2 mm
[0.0787 in.]
Check the governor system in the gear case. If any
parts are found defective, repair or replace them.
12.7 Disassembly and reassembly
of governor levers
12.7.1 Disassembling shaft
A
Section A-A
Gear case
Figure 54 Reassembling governor shaft
1. Remove the expansion plug, paying attention not
to scratch the gear case.
2. Pull out the grooved pin.
12.7.2 Reassembling Shaft
1. Reassemble the shaft in the reverse sequence of
disassembly.
2. After reassembling the shaft, press-fit the
expansion plug into the shaft hole in the gear case.
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
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Page 58
GEAR CASE AND OIL PUMP ENGINE MAIN PARTS
Tightening torque:
39.2 to 49.0 N·m
(4.0 to 5.0 kgf·m)
[28.93 to 36.17 lbf·ft]
Taper plug tightening
torque:
14.7 to 21.6 N·m
(1.5 to 2.2 kgf·m)
Sealant: HERMESEAL H1
or THREE-BOND 1344
[10.85 to 15.91 lbf·ft]
Figure 55 Gear case assembly
Tightening torque:
7.85 to 9.80 N·m
(0.8 to 1.0 kgf·m)
[5.79 to 7.23 lbf·ft]
12.8 Installation of gear case
assembly
Figure 56 Installing gear case assembly
58 / 155
ENGLISH
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 59
ENGINE MAIN PARTS
TIMING GEARS
ENGINE MAIN PARTS
13 TIMING GEARS
13.1 Disassembly
Figure 57 Timing gear component parts
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Disassembly sequence
1. Crankshaft gear
2. Idle gear
3. Camshaft gear
4. Injection pump camshaft gear
ENGLISH
59 / 155
Page 60
TIMING GEARS ENGINE MAIN PARTS
13.2 Removal
1. Remove the snap ring and remove the idle gear.
Figure 58 Removing idle gear
2. Since camshaft gear is press-fitted, remove
camshaft gear (valve-cam and injection pump
cam) only after disassembling the shaft
independently.
3. Remove the crankshaft gear as same procedure
as camshaft gear.
Figure 59 Removing camshaft gear
Injection pump
camshaft gear
Check tooth faces
and end surfaces for
wear and damage.
Idle gear
Crankshaft gear
Valve camshaft gear
13.3 Inspection
Check the removed gears. If any gear is found
defective, replace it.
Description Standard Value Service Limit
Clearance
between
bushing and
shaft
Table 22 Idle gear bushing, unit in mm [in.]
Description Standard Value Service Limit
Crankshaftidle
Idle-camshaft
Idle-fuel
pump gear
0.03 to 0.07
[0.0012 to 0.0028]
0.01 to 0.14
[0.0004 to 0.0055]
0.2
[0.0079]
0.3
[0.0118]
Figure 60 Inspecting timing gears
60 / 155
ENGLISH
Table 23 Backlash between gears after installation,
unit in mm [in.]
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 61
ENGINE MAIN PARTS
Figure 61 Timing gears in alignment
TIMING GEARS
13.4 Installation of timing gears
1. Press-fit the crankshaft gear onto the shaft.
2. Press-fit the gears to the camshaft (valve camshaft
and injection pump camshaft).
3. Install the gears in the following sequence.
a Turn the crankshaft to set the No. 1 cylinder to
top dead center on compression stroke.
b Install the valve camshaft and injection pump
camshaft.
c Install the idle gear aligning with the timing
marks of other gears.
d Confirm the positions of timing gears again.
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
61 / 155
Page 62
CAMSHAFTS (VALVE AND INJECTION PUMP) ENGINE MAIN PARTS
ENGINE MAIN PARTS
14 CAMSHAFTS (VALVE
AND INJECTION PUMP)
14.1 Disassembly
13
12
L2
10
5
11
L3
9
6
7
Figure 62 Camshaft component parts
10
L2
1
4
2
3
1
6
7
Disassembly sequence
1. Camshaft (Valve)
2. Camshaft gear
3. Ball bearing (Front)
4. Woodruff key
5. Sunk key
6. Camshaft stopper washer
7. Bolt
8. Tappet
9. Pushrod
10. Camshaft (Injection pump)
11. Camshaft gear
12. Ball bearing (Rear)
13. Snap ring
8
L3
62 / 155
ENGLISH
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 63
ENGINE MAIN PARTS
CAMSHAFTS (VALVE AND INJECTION
PUMP)
14.2 Removal of Valve Camshaft
14.2.1 Remove only the valve camshaft
When it is necessary to remove only the valve
camshaft, use the following procedure:
1. Dismount the cylinder head assembly.
2. Pull out the pushrods.
3. Pull out the tappets.
4. Remove the gear case assembly.
5. Remove the camshaft stopper bolt.
6. Draw out the camshaft assembly.
14.2.2 Removal of the injection pump
camshaft
1. Disconnect the injection pipes.
2. Remove the injection pump assembly.
3. Remove the gear case assembly.
4. Remove the shaft rear cover.
5. Remove the stopper bolt.
6. Pull out the shaft to the front side.
Figure 63 Removing injection pump camshaft
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
63 / 155
Page 64
CAMSHAFTS (VALVE AND INJECTION
PUMP) ENGINE MAIN PARTS
14.3 Inspection
Check the removed parts. If any parts are found
defective, repair or replace them.
Cam lobe-wear
and damage
Each ball bearing-wear
and noise
Journal bearing-wear
and damage
Bend
Rod end-wear
and damage
Cam contact surface-wear
and damage
Figure 64 Inspection of camshafts
64 / 155
Oldham’s coupling-wear
ENGLISH
Cam lobe-wear
and damage
Standard
value
Major diameter of injection
pump cam
Major diameter of valve cam 27.37
30
[1.1811]
[1.0776]
Service
limit
-0.7
[-0.0276]
-1.0
[-0.0394]
Table 24 Inspection of camshafts, unit in mm [in.]
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 65
ENGINE MAIN PARTS
Figure 65 Installing valve camshaft
CAMSHAFTS (VALVE AND INJECTION
PUMP)
14.4 Installation
When installing the camshafts, pay attention to the
following:
1. Apply oil to the bearings and cam lobes.
2. Reassembly sequence of the camshaft is the
reverse of disassembly.
3. Align the timing marks on the gears to the marks
on the idler gear.
4. After installation, check and adjust fuel injection
timing and valve clearances.
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
65 / 155
Page 66
PISTON AND CONNECTION ROD ENGINE MAIN PARTS
ENGINE MAIN PARTS
15 PISTON AND
CONNECTION ROD
15.1 Disassembly
1
2
3
4
5
Figure 66 Piston and connecting rod component
parts
9
6
7
8
10
Disassembly sequence
1. Piston ring No. 1
2. Piston ring No. 2
3. Oil ring
4. Piston
5. Piston pin
6. Connecting rod
7. Connecting rod bearing
8. Connecting rod cap
9. Connecting rod bolt
10. Connecting rod nut
66 / 155
ENGLISH
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 67
ENGINE MAIN PARTS
Figure 67 Removing connecting rod and piston
Pressing
PISTON AND CONNECTION ROD
15.2 Removal
1. Remove the cylinder head assembly.
2. Remove the oil pan.
3. Remove the oil screen.
4. Mark the cylinder number on the side face of big
end of each connecting rod to prevent confusion at
reassembly.
5. Remove the connecting rod cap from each
connecting rod piston assembly, and pull the
assembly upward.
Be careful not to allow the connecting rod to
scratch the crankshaft pin and cylinder.
Place the removed parts (connecting rod, rod cap,
piston, etc.) classifying by each cylinder.
6. Remove the rings from each piston by the piston
ring pliers.
Pushrod
Piston pin
FRONT
mark
(arrow)
Piston
Connecting rod
Identification mark
Figure 68 Removing piston pin
Tool body
Special tool Part No.
Piston ring pliers 31391-12900
Table 25 Piston ring pliers
7. Using the piston pin setting tool, push out the
piston pin from each piston.
Special tool Part No.
for L2A, L3A, 30L91–00030
Piston pin setting
tool
for L2C, L3C, 30L91–00020
for L2E. L3E, 30L91–10010
Table 26 Piston pin setting tool
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
67 / 155
Page 68
PISTON AND CONNECTION ROD ENGINE MAIN PARTS
15.3 Inspection
Inspect the removed parts. If any parts are found
defective, replace or repair them.
• Wear, seizure and
streaks
• Clearance between
piston and cylinder.
Standard: 0.07 to
0.115 mm [0.0028 to
0.0045 in.]
• Wear of piston ring
grooves
Damage, wear,
and ring gap
Damage and wear
Damage, wear, and ring gap
Journal bearing-
wear and damage
Damage
• Bend and twist
• Big end play.
Standard: 0.1 to 0.35
mm [0.0039 to 0.0138
in.]
• Contact and seizure
• Flaking and fusion
• Oil clearance.
Standard: 0.028 to
0.071 mm [0.0011 to
0.0028 in.]
Figure 69 Inspection of piston and connecting rod
Piston
Cylinder
Ring
Ring gaps
Figure 70 Measuring ring gap
15.3.1 Inspection of piston ring gaps
Place each piston ring into the cylinder bore and push
the ring with piston to have square position to the
cylinder wall. Measure the ring gap with feeler gages. If
the measurement exceeds service limits, replace that
piston ring.
Ring Standard Service Limit
No. 1
No. 2
Oil 0.15 to 0.35
Table 27 Inspection of camshafts, unit in mm [in.]
0.15 to 0.30
[0.0059 to 0.0118]
1.5 [0.059]
[0.0059 to 0.0138]
68 / 155
ENGLISH
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 69
ENGINE MAIN PARTS
PISTON AND CONNECTION ROD
CAUTION
a. When only the replacement of rings are to be
made, without reboring (honing) of the cylinder,
measure the ring at less worn portion of the
cylinder bore.
b. When replacing rings, make sure to install the
new rings having the same size as the piston.
c. Piston rings available for servicing are sized by
three classes: STD, 0.25 OS, and 0.50 OS.
15.3.2 Inspection of ring groove in piston
Measure the side clearance between each piston ring
and ring groove of the piston. If the service limit is
exceeded, replace the ring with new one. If the
clearance still exceeds the service limit, replace the
piston with new one.
Ring Standard Service Limit
Figure 71 Measuring ring side clearance
No. 1 — 0.3 [0.0118]
No. 2 0.05 to 0.09
[0.0020 to 0.0035]
Oil 0.03 to 0.07
[0.0012 to 0.0028]
Table 28 Inspection of ring groove in piston, unit in
mm [in.]
0.2 [0.0079]
0.2 [0.0079]
NOTE
No. 1 ring is the semi-key stone type ring.
15.4 Installation
When reassembling the piston and connecting rod and
installing the piston-and-rod assemblies in the cylinder
block, pay attention to the following:
1. Reassembling the piston and connecting rod Using
the piston pin setting tool, press the piston pin into
the set position.
Figure 72 Installation of piston and connecting rod
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Table 29 Piston pin setting tool
ENGLISH
Special tool Part No.
Piston pin setting tool ST332400
69 / 155
Page 70
PISTON AND CONNECTION ROD ENGINE MAIN PARTS
Description Standard
Piston pin
FRONT mark (arrow)
Piston
Guide
Pressing
Pin press-fitting force
(at a normal temperature)
Table 30 Pin press-fitting force
Push rod
Connecting rod
Identification mark
1000 ±500 kg
[2205 ±1102 lb]
Tool body
Base plug
Figure 73 Reassembling piston pin
Guide “LA” (92 l): for L2A, L3A
Guide “LC” (89.5 l): for L2C, L2E, L3C, L3E
70 / 155
ENGLISH
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 71
ENGINE MAIN PARTS
PISTON AND CONNECTION ROD
2. Installation of piston rings
FRONT mark
Rod front mark
Align lugs accurately
each other.
Tightening torque:
31.4 to 34.3 N²m
(3.2 to 3.5 kgf²m)
[23.15 to 25.32 lbf²ft]
Figure 74 Reassembly of piston rings and
connecting rod cap
Ring set positions:
No. 1 ring,
No. 2 ring,
oil ring
“T” mark and OS size mark
“T” mark and OS size mark
OS size identification paint
Color of discrimination:
STD = Without color
0.25 = White
0.50 = Blue
Oil ring gap
Front
No. 2 ring gap
No. 1 ring gap
Coil expanded
joint of oil ring
Figure 75 Proper arrangement of ring gaps
3. Set the piston ring gaps to the proper positions as
shown at right. Apply oil to the rings and cylinder
wall.
4. Using a piston-ring compressor to compress the
rings into the grooves, push the piston-andconnecting rod assembly down into the cylinder.
Be careful not to break the rings by knocking the
head of piston excessively. Note that the front
marks on the piston and connecting rod are in
direction of the engine front.
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
71 / 155
Page 72
PISTON AND CONNECTION ROD ENGINE MAIN PARTS
5. Apply engine oil to the bearing surface of the
connecting rod caps. Fit each cap to the
connecting rod using match marks placed before
removal as a guide. In the case of a new rod which
does not have such a match mark, position the
lugs (provided for preventing the bearing from
rotating) on the same side.
Figure 76 Fitting cap to connecting rod
72 / 155
ENGLISH
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 73
ENGINE MAIN PARTS
4
CRANKSHAFT
ENGINE MAIN PARTS
16 CRANKSHAFT
16.1 Disassembly
2
2
5
6
7
5
11
10
1
9
1
1
1
8
13
12
Figure 77 Crankshaft component parts
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Disassembly sequence
1. Key
2. Crankshaft
3. Crankshaft gear
4. Crankshaft pulley
5. Nut
6. Washer
7. Spring washer
8. Flywheel
9. Ring gear
10. Rear oil seal
11. Rear oil seal case
12. Gasket
13. Flywheel bolt
ENGLISH
73 / 155
Page 74
CRANKSHAFT ENGINE MAIN PARTS
16.2 Removal
1. Loosen the flywheel bolts and remove the
flywheel.
2. Unscrew the crankshaft pulley nut and remove the
crank pulley.
3. Remove the rear oil seal case assembly.
4.
5. Remove the main bearing caps. Keep each set of
removed bearings together with its bearing cap.
6. Remove the crankshaft.
16.3 Inspection
Figure 78 Removing main bearing cap
Inspect the removed parts. If any parts are found
defective, repair or replace them.
• Journals and pins - damage and
uneven wear
• Cracks, clogging of oil hole, and
bend
• Wear of journal contact surface
Damage to tooth face
Wobble of pulley
Wobble
Damage to tooth face
Wear and damage
Figure 79 Inspection of crankshaft and flywheel
74 / 155
ENGLISH
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 75
ENGINE MAIN PARTS
CRANKSHAFT
16.3.1 Checking the crankshaft for wear
To check the crankpins and main journals for
cylindricity and roundness, measure the diameter of
each crankpin and main journal at two places 1 and 2 in
directions “A” and “B” for a total of 4 measurements in
the figure at right. If necessary, regrind the crankpins
and main journals to the next under size. If any
crankpin or main journal has been worn out beyond the
service limit, replace the crankshaft.
Ring Standard Service Limit
Figure 80 Measuring ring gap
Figure 81 Measuring main bearing I. D.
Main journal
diameter
Crankpin
diameter
Table 31 Diameter of crankpin and main journal
(mm [in.])
Ring Standard Service Limit
0.25 US
0.50 US
Table 32 Undersize diameters (mm [in.])
43 [1.6929] -0.70 [-0.0276]
40 [1.5748] -0.70 [-0.0276]
42.715 to 42.730
[1.6817 to 1.6823]
42.465 to 42.480
[1.6718 to 1.6724]
39.715 to 39.730
[1.5636 to 1.5642]
39.465 to 39.480
[1.5537 to 1.5543]
16.3.2 Inspection of crankshaft oil
clearance
Oil clearance is calculated by subtracting the diameter
of main journal and crankpin from the inside diameter
of main bearing and rod bearing. To check the main
bearings and rod bearings for tapering wear and out-ofround wear, inside diameter of each main bearing and
rod bearing should be measured, after its bearing-cap
is fastened to the specified torque, at two places along
the bearing, in two directions “A” and “B” each place, as
shown in the figure at right. If necessary, replace the
worn bearing with new one. If oil clearance still
exceeds the service limit, regrind the crankshaft to the
next under size and replace the bearing with one of the
corresponding under size.
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
CAUTION
A crankshaft, which has been seized, cannot be
reground to any under size.
ENGLISH
75 / 155
Page 76
CRANKSHAFT ENGINE MAIN PARTS
Description Standard
Main bearing cap bolt
Rod bearing cap nut
Table 33 Tightening torque N·m (kgf·m) [lbf·ft]
Description Standard
Main bearing 0.10 [0.0039]
Rod bearing 0.15 [0.0059]
Table 34 Oil clearance (mm [in.])
49.0 to 53.9 (5.0 to 5.5)
[36.17 to 39.78]
31.4 to 34.3 (3.2 to 3.5)
[23.15 to 25.32]
16.4 Replacement of crankshaft rear oil seal
When reassembling the piston and connecting rod and
installing the piston-and-rod assemblies in the cylinder
block, pay attention to the following:
1. Pry the oil seal out with a screwdriver.
2. Drive in a new oil seal to the oil seal case.
76 / 155
ENGLISH
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 77
ENGINE MAIN PARTS
Cap tightening torque:
49.0 to 53.9 N·m
(5.0 to 5.5 kgf·m)
[36.17 to 39.78 lbf·ft]
Direction of
cap installation
CRANKSHAFT
16.5 Installation
When installing the crankshaft, pay attention to the
notes given in the figure below.
Thrust bearing only for No. 2 cap
Side seals coated with sealant
(THREE-BOND 1212)
Front
Crankshaft end play:
0.05 to 0.175 mm
[0.0020 to 0.0069 in.]
Figure 82 Installation of crankshaft
Round end down
Place cap flush with the
end face of cylinder block.
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
77 / 155
Page 78
CYLINDER BLOCK ENGINE MAIN PARTS
ENGINE MAIN PARTS
17 CYLINDER BLOCK
17.1 Disassembly
11
10
1
1
9
2
5
5
5
5
3
3
3
3
5
3
4
8
7
6
5
5
3
3
Figure 83 Cylinder block component parts
Disassembly sequence
1. Cylinder block
2. Front plate
3. Bearing cap
4. Cover
5. Main bearing
6. Starter bracket
7. Rear oil seal
8. Oil seal case
9. Idler gear shaft
10. Oil filter shaft
11. Oil level gage guide
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ENGLISH
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 79
ENGINE MAIN PARTS
Figure 84 Measuring cylinder bore
CYLINDER BLOCK
17.2 Inspection
Inspect the cylinder block. If it is found defective, repair
or replace the block.
Model Standard Service limit
L2A, L3A
L2C, L3C
L2E, L3E
65
0
+0.0012
[2.5591 ]
0
+0.03
70
0
[2.7559 ]
[2.9921 ]
+0.0012
0
+0.03
76
0
+0.0012
0
+0.7
[+0.0276]
+0.7
[+0.0276]
+0.7
[+0.0276]
+0.03
Table 35 Cylinder bore (mm [in.])
17.3 Reboring of cylinder
Approx. 10 mm [0.40 in.]
from upper end
Center
Lower
Measuring position
Front
Direction of measuring
Figure 85 Cylinder bore measuring positions
When reboring a cylinder, use the following procedure :
1. Selecting a piston
Piston service size
0.25 OS or 0.50 OS
2. Measuring the piston diameter
3. Reboring finish dimension =
[Piston OD] + [Clearance] –
[Honing allowance (0.02 mm [0.00079 in.])]
Description Standard
Clearance
(between piston and
cylinder)
0.071 to 0.084
[0.00280 to 0.00331]
(A to D)
Table 36 Oil clearance (mm [in.])
Figure 86 Measuring piston diameter
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
CAUTION
When it is necessary for a cylinder to be rebored to
the next over size, other cylinders must also be
rebored to the same over size.
ENGLISH
79 / 155
Page 80
CYLINDER BLOCK ENGINE MAIN PARTS
80 / 155
ENGLISH
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 81
LUBRICATION SYSTEM
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
81 / 155
Page 82
GENERAL LUBRICATION SYSTEM
LUBRICATION SYSTEM
18 GENERAL
18.1 Specification
1
Description Specification
Lubricating system and filtering system Pressure-feed lubricating, full-flow filtering
Oil capacity (Upper limit/lower limit):
excluding 0.5 l for oil filter
l [U.S.gal]
Oil pump
Relief valve opening pressure 0.3±0.03 MPa (3.0±0.3 kgf/cm2) [42.68±4.27 psi ]
Lamp lighting and valve opening pressure
(Differential pressure)
Oil filter
Type Gear type (Inner and outer gears in mesh) enclosed in gear case
Driving method Direct drive by crankshaft
Type Paper-element cartridge type
Relief valve opening
pressure
L2: 2.4/1.4
[0.6341/0.3699]
0.05±0.01 MPa (0.5±0.1 kgf/cm2) [7.11±1.42 psi]
0.1±0.02 MPa (1.0±0.2 kgf/cm2) [14.23±2.85 psi]
L3: 3.0/1.5, 3.6/1.8 or 4.8/3.0
[0.7926/0.3963, 0.9511/0.4756 or
1.2682/0.7926]
Table 37 Specification lubrication system
For the oil pump, which is enclosed in the gear case,
see Group 2 Engine Main Parts
18.2 Special tools
Tool name Part No Shape Use
Removal and installation of oil
pressure switch
Socket wrench MD998054
82 / 155
ENGLISH
1. All specifications are subject to change without any prior
notice.
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 83
LUBRICATION SYSTEM
OIL FILTER AND OIL PRESSURE SWITCH
LUBRICATION SYSTEM
19 OIL FILTER AND OIL
PRESSURE SWITCH
19.1 Disassembly
Figure 87 Oil filter and pressure switch
Disassembly sequence
1. Oil filter
2. Oil pressure switch
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
83 / 155
Page 84
OIL FILTER AND OIL PRESSURE SWITCH LUBRICATION SYSTEM
19.2 Removal and installation
1. Remove the filter by the filter wrench.
2. Remove the oil pressure switch by the special tool
named socket wrench.
Special tool name Part No.
Socket wrench MD998054
Table 38 Special tool
Figure 88 Installing oil filter
Figure 89 Installing pressure switch
3. Apply engine oil to the O-rings. Pay attention not to
twist the O-rings.
4. Apply sealant (HERMESEAL H1 or THREE-BOND
1314) to the threads of the oil pressure switch
before installation.
5. Install the oil filter by hands.
CAUTION
After installation, check for oil leak while the engine is
running.
19.3 Inspection
Inspect the following.
19.3.1 Oil leak
Pressure switch ON
pressure:
0.05±0.01 MPa
(0.5±0.1 kgf/cm2)
[7.11±1.42 psi]
Figure 90 Inspecting oil filter and oil pressure switch
84 / 155
ENGLISH
Table 39 Pressure
CAUTION
Check the oil filter for contamination. If necessary,
clean the engine interior with flushing oil.
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 85
FUEL SYSTEM
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
85 / 155
Page 86
GENERAL FUEL SYSTEM
FUEL SYSTEM
20 GENERAL
INJECTION
PUMP
20.1 Specifications
1
Specification
Description
L2 L3
Type In-line type (Bosch NC)
Direction of rotation Clockwise (as viewed from driving side)
Injection order 1–2 1–3–2
Fuel injection timing
if the rated speed "n"
is:
Plunger diameter ø 6 mm [0.2362 in.]
Number of plungers 2 3
MS retard 4° (for crank)
Delivery valve Silt or Bosch
Type Thread type
a
n ≤ 2000 rpm 15° bTDC
2000 ≤ n ≤ 3000 rpm 17° bTDC
n = 3600 rpm 19° bTDC
INJECTION
NOZZLE
FUEL
PUMP
(optional)
Nozzle, type Throttle type
Nozzle, number of jets 1
Injection pressure 13.7 MPa (140 kg/cm
Type Electromagnetic diaphragm type
Delivery 0.37 l [0.0977 U.S.gal]/min (12V, at 20°C [68°F])
Type Electromagnetic plunger type
Delivery, common type
Delivery, compact type
Type Mechanical drive type
Delivery 0.225 l [0.0594 U.S.gal]/min
Table 40 Specifications
2
) [1991.5 psi]
0.9 l/min [0.2378 U.S.gal/min] (12V, at 20°C [68°F])
0.4 l/min [0.1057 U.S.gal/min] (12V, at 20°C [68°F])
86 / 155
ENGLISH
1. All specifications are subject to change without any prior
notice.
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 87
FUEL SYSTEM
Type Solenoid pull hold type
GENERAL
Specification
Description
L2 L3
Rated current, pull
Rated current, hold
FUEL
CUTT OFF
VALVE
FUEL FILTER Paper-element type
Working voltage 12V, DC
Stroke 13.5 mm [0.5315 in.]
Type Solenoid, push out type
Coil resistance 1.6Ω±10% (at 20°C [68°F])
Stroke 10 mm [0.3937 in.]
55A
1.0A
Table 40 Specifications
a. Please refer to the applicable engine model specification sheet for actual data
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
87 / 155
Page 88
GENERAL FUEL SYSTEM
20.2 Disassembly
5
L2
3
3
L3
4
L2
1
L3
1
2
2
7
6
Figure 91 Fuel system component parts
88 / 155
ENGLISH
Disassembly sequence
1. Injection pump
2. Adjusting shim
3. Injection pipe
4. Injection nozzle
5. Return pipe
6. Fuel filter
7. Fuel cutoff solenoid
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 89
FUEL SYSTEM
FUEL INJECTION PUMP
FUEL SYSTEM
21 FUEL INJECTION PUMP
21.1 Disassembly
Figure 92 Injection pump component parts
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Disassembly sequence
1. Union collar
2. Air vent screw
3. Delivery valve holder
4. Valve spring
5. Holder stopper
6. Housing
7. O-ring
8. Delivery valve
9. Gasket
10. Seat valve
11. Plunger barrel
12. Sleeve
13. Upper seat
14. Plunger spring
15. Plunger
16. Lower seat
17. Adjusting shim
18. Tappet roller
19. Pin
20. Control rack
21. Stop wire bracket
ENGLISH
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Page 90
FUEL INJECTION PUMP FUEL SYSTEM
21.2 Inspecting the injection pump
while operating the engine
Never attempt to disassemble the pump unless it is
necessary.If the pump is assumed defective, it is
recommended to replace the pump assembly.
Item
Idling speed
Exhaust
smoke color
Fuel cut-off
solenoid
Table 41 Inspection injection pump
Inspection
procedure
Measure engine
speed
1. Quickly
accelerate
engine without
load.
2. Apply load to
Turn ignition switch
to OFF from ON.
900 rpm
No remarkably
blacksmoke
exhaust
permitted.
A solenoid
acting sound.
21.3 Removal
1. Disconnect the fuel injection pipes.
2. Remove the tie-rod clip cover.
3. Remove the tie-rod clip and tie-rod.
4. Remove the injection pump assembly.
21.4 Disassembly
Criteria
Figure 93 Removing injection pump
1. Remove the stopper plate.
2. Unscrew the delivery holder. Remove the delivery
valve and valve spring.
3. Remove the tappet roller and stopper pin.
4. Remove the tappet, plunger spring, etc.
CAUTION
a. When replacing the plunger barrel, delivery
valve, etc., do not loosen the adjusting screw and
plate of each cylinder.
b. When those parts have been replaced, it is
necessary to measure fuel injection quantity by
using the pump tester and cam box.
c. All removed parts from the pump should be
classified by cylinders and immersed in clean
fuel.
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ENGLISH
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 91
FUEL SYSTEM
Control rack
movement
(uneven)
FUEL INJECTION PUMP
21.5 Inspection
Inspect all removed parts, if any part is found defective,
replace it.
O-ring-Cracks
and deterioration
Wear and scratch
PlungerInterference, wear,
scratch, rust,
seizure
Interference, wear
Figure 94 Inspection of injection pump
Figure 95 Direction of reassembly of plunger
21.6 Reassembly of plunger
1. Insert the plunger barrel into the housing.
2. Install the delivery valve and valve spring.
Temporarily tighten the holder.
3. Insert the control rack.
4. Insert the control pinion. Align the matchmark of
the rack to that of the pinion.
5. Install the spring upper seat.
6. Insert the plunger spring.
7. Fit the lower seat to the plunger. Insert the plunger
into the barrel side.
8. Press the tappet roller assembly and install the
stopper pin.
9. Tighten the delivery holder.
21.7 Reassembly of delivery valve
Reassemble the injection pump in the reverse
sequence of removal.
34.3 to 38.2 N·m
(3.5 to 3.9 kgf·m)
[25.32 to 28.21 lbf·ft]
Figure 96 Installation of delivery valve holder
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
CAUTION
a. When installing the plunger barrel, engage the
b. Position the part-number stamp of the plunger to
c. After installation, check for proper injection
ENGLISH
dowel pin on the housing side with the groove in
the barrel.
the opposite side of the rack (engage the feed
hole with the plunger lead).
timing.
91 / 155
Page 92
INJECTION NOZZLE FUEL SYSTEM
FUEL SYSTEM
22 INJECTION NOZZLE
22.1 Disassembly
Figure 97 Nozzle holder assembly component parts
92 / 155
ENGLISH
Disassembly sequence
1. Body sub-assembly
2. Shim washer
3. Pressure spring
4. Pin
5. Distance piece
6. Nozzle assembly
7. Retaining nut
22.2 Removal
1. Disconnect the injection pipe and fuel return pipe.
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 93
FUEL SYSTEM
INJECTION NOZZLE
2. Remove the injection nozzle assembly from the
cylinder head.
CAUTION
a. Attach an identification-number tag to the
removed injection nozzle.
b. Plug the openings, to prevent entering of dust,
water and other foreign particles into the pipes
and combustion chamber.
c. Do not mix the parts of any nozzle assy with
others, but keep the parts of each nozzle
assembly as a unique combination.
22.3 Disassembly
If the removed nozzle assembly is assumed defective,
disassemble the assembly and repair or replace the
defective parts.
1. Grip the nozzle holder body in a vise. Loosen the
retaining nut. Never vise the retaining nut to
prevent deformation.
2. Remove the shim washer, pressure spring,
distance piece and nozzle assembly.
CAUTION
Scrape off carbon deposit with a wooden piece. Keep
the removed parts immersed in washing oil
(kerosene). Pay special attention not to scratch the
needle valve in the nozzle assembly.
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
93 / 155
Page 94
INJECTION NOZZLE FUEL SYSTEM
22.4 Inspection
Never attempt to disassemble the pump unless it is
necessary.If the pump is assumed defective, it is
recommended to replace the pump assembly.
Fatigue and break
Wear
Deformation
Poor contact
While immersed in
kerosene, check for
smooth sliding.
and break
Figure 98 Inspecting nozzle
Tightening torque:
24.5 to 29.4 N·m
(2.5 to 3.0 kgf·m)
[18.08 to 21.70 lbf·ft]
Figure 99 Assembling the nozzle
Tightening torque:
34.3 to 39.2 N·m
(3.5 to 4.0 kgf·m)
[25.32 to 28.93 lbf·ft]
Return pipe
22.5 Assembly
1. Insert the nozzle assembly into the retaining nut so
that the nozzle is correctly seated in the nut.
2. Place the distance piece, retaining pin, pressure
spring and shim washer on the nozzle tip.
3. Tighten the nozzle holder body fully by hand
4. Grip the nozzle holder in a vise. Tighten the
retaining nut to the specified torque.
CAUTION
If required, always replace the nozzle as a complete
assy.
22.6 Adjustment
Adjust injection starting pressure by increasing or
decreasing the thickness of inserting shim washer.
Varying shim thickness by 0.1 mm [0.0039 in.] causes
injection start pressure to change 0.98 MPa
cm
2) [142.3 psi].
(10 kgf/
Figure 100 Testing nozzle
94 / 155
ENGLISH
Available shims:
10 kinds of shims available from 1.25 mm to 1.7 mm
[0.0492 to 0.0669 in.] in thickness, in increment of 0.05
mm [0.0020 in.].
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 95
FUEL SYSTEM
INJECTION NOZZLE
Standard Allowable limit
Idling speed Measure engine speed
13.7 MPa (140 kgf/cm
[1992 psi]
Table 42 Injection start pressure
2
)
12.7 MPa (130 kgf/cm2)
[1849 psi] or less
49.0 to 58.8 N·m (5.0 to 6.0 kgf·m) [36.17 to 43.40 lbf·ft]
Figure 101 Installing nozzle holder
Fuel return pipe
24.5 to 29.4 N·m
(2.5 to 3.0 kgf·m)
[18.08 to 21.70 lbf·ft]
Injection pipe
2 4 . 5 t o 2 9 . 4 N · m
(2.5 to 3.0 kgf·m)
[18.08 to 21.70 lbf·ft]
22.7 Installation
1. Clean the nozzle holder fitting surface of the
cylinder head. Install the nozzle holder with a
gasket.
2. Connect the fuel return pipe and injection pipe.
Figure 102 Installing injection pipe
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
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Page 96
INJECTION NOZZLE FUEL SYSTEM
96 / 155
ENGLISH
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 97
GOVERNOR SYSTEM
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
97 / 155
Page 98
GENERAL GOVERNOR SYSTEM
GOVERNOR SYSTEM
23 GENERAL
23.1 Specification
Governor type Centrifugal flyweight
type
Table 43 Specification
98 / 155
ENGLISH
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
Page 99
GOVERNOR SYSTEM
GENERAL
23.2 Disassembly
Figure 103 Governor system component parts
Disassembly sequence
1. Sealing metal
2. Sealing wire
3. Low and high-speed bolt
4. Governor weight assembly
5. Sliding shaft
6. Stopper
7. Governor spring
8. Governor shaft
9. Governor level
10. Tie-rod
11. Tie-rod clip
12. Tie-rod cover
13. Tie-rod cover gasket
14. Tension lever
15. Start spring
16. Governor spring lever
17. Speed control lever assembly
18. Cover assembly
19. Governor cover gasket
20. Return spring
21. Stop lever assembly
22. O-ring
23. Snap ring
24. Stop lever
25. Grooved pin (3 x 20)
26. Grooved pin (3 x 16)
27. Torque spring set
28. Sealing cap
Service Manual Mitsubishi L-Series diesel engines
Version 08/2004
ENGLISH
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Page 100
TORQUE SPRING GOVERNOR SYSTEM
GOVERNOR SYSTEM
For installation and
adjustment
For installation and
adjustment
24 TORQUE SPRING
24.1 Installation of torque spring
set
Never tamper
with this screw.
Turn in this torque
spring set until
engine speed
drops about 50
For installation
and adjustment
For installation and
adjustment
min-1 from highidling speed.
Figure 104 Torque spring set
Identification
paint mark
Adjust to
specified
number of
loosening
turns “N”
Number of
loosening
turns “N”
Approx. 2 mm [0.0787 in.]
(before installation)
Install and adjust the torque spring set using the
following procedure:
1. Set the speed control lever to the high-idling speed
position by adjusting the high-speed set bolt.
2. Turn in the torque spring set until engine speed
drops about 50 rpm from high-idling speed.
3. From this position, turn back the torque spring set
by the specified number of turns (N). Lock the
torque spring set at the position with the special
nut.
4. Install the torque spring set sealing cap and make
sure to tighten the cap to prevent loosening.
CAUTION
There are two types of torque spring set: The single
spring type and the double-spring type. Since each
torque spring set has been adjusted precisely in the
manufacturer’s factory, do not tamper with the adjust
screw unless it is necessary.
24.2 Assembling the torque spring
set
When the torque spring set has been disassembled or
its component parts have been replaced, reassemble
and adjust the torque spring set using the procedure
mentioned below:
Screw
Nut
Special
nut
Case
Stopper
Spring
Figure 105 Assembling torque spring set
Model Number of loosening turns
L2A-61DA, L2A-62A, L2A-62DA, L2A-61DM 2.1
L3A-61DA, L3C-63WM 2.2
L2C-61RR, L2E-61IR, L3A-62DA, L3C-61ES 2.3
L2A-61A, L2A-61RR, L2A-61SS, L2A-62SS, L2A-62SDG, L2C-62A,
L2C-62DA, L2E-62WM, L2E-W262WM, L3A-61A, L3A-62A, L3A-61BG,
L3A-61RG, L3C-61A, L3C-62A, L3C-61DA, L3C-61RT
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ENGLISH
Service Manual Mitsubishi L-Series diesel engines
2.4
Version 08/2004
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