Mitsubishi ENGINE ELECTRICAL SPECIFICATIONS

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ENGINE

ELECTRICAL

CONTENTS

16-1

CHARGING SYSTEM 2................

GENERAL INFORMATION 2................

SERVICE SPECIFICATIONS 3..............

SPECIAL TOOL 3.........................

ON-VEHICLE SERVICE 4..................

Alternator Output Line Voltage Drop Test 4....

Output Current Test 5.......................

Regulated Voltage Test 7....................

Waveform Check Using An Analyzer 9........

Alternator Relay Continuity Check 10.........

ALTERNATOR 11..........................

STARTING SYSTEM 17................

GENERAL INFORMATION 17..............

SERVICE SPECIFICATIONS 17............

IGNITION SYSTEM 25.................

GENERAL INFORMATION 25..............

SERVICE SPECIFICATIONS 26............

ON-VEHICLE SERVICE 26................

Ignition Coil (With Built-in Power Transistor)

Check 26...................................

Spark Plug Check and Cleaning 27...........

Camshaft Position Sensor Check 28.........

Crank Angle Sensor Check 28...............

Detonation Sensor Check 28.................

IGNITION COIL 29.......................

CRANK ANGLE SENSOR 29..............

CAMSHAFT POSITION SENSOR 30.......

DETONATION SENSOR 31................

STARTER MOTOR 18.....................

16-2

ENGINE ELECTRICAL -

CHARGING SYSTEM

GENERAL INFORMATION

The charging system uses the alternator output to keep the battery charged at a constant level under various electrical loads.

Charging System

Voltage

OPERATION

Rotation of the excited field coil generates AC voltage in the stator. This alternating current is rectified through diodes to DC voltage having a waveform shown in the illustration at left.

Approx. 14.4 V

The average output voltage fluctuates slightly with the alternator load condition.

Time

When the ignition switch is turned on, current flows in the field coil and initial excitation of the field coil occurs. When the stator coil begins to generate power after the engine is started, the field coil is excited by the output current of the stator coil. The alternator output voltage rises as the field current increases and it falls as the field current decreases. When t he battery voltage (alternator S terminal voltage) reaches a regulated voltage

SYSTEM DIAGRAM

<4G9>

of approx. 14.4 V, the field current is cut off. When the battery voltage drops below t he regulated voltage, the voltage regulator regulates the output voltage to a constant level by controlling the field current. In addition, when the field current is constant, the alternator output voltage rises as the engine speed increases.

Stator coil

Field coil

Voltage regulator

Engine-ECU

G S

Charging warning lamp

Ignition switch

Battery

<4G6>

ENGINE ELECTRICAL -

Stator coil

Field coil

Voltage regulator

Charging System

Engine-ECU

Charging warning lamp

Ignition switch

16-3

Battery

ALTERNATOR SPECIFICATIONS

Items 4G9 4G6

Type Battery voltage sensing Battery voltage sensing

Rated output V/A 12/85 <Except cold climate zone>

12/100 <Cold climate zone>

Voltage regulator Electronic built-in type Electronic built-in type

12/100

SERVICE SPECIFICATIONS

Items Standard value Limit

Alternator output line voltage drop (at 30A) V - max. 0.3

Regulated voltage ambient -20_C 14.2- 15.4 temp. at voltage regulator V

20_C 13.9- 14.9 -

60_C 13.4- 14.6 -

80_C 13.1- 14.5 -

Output current - 70% of normal output current

Rotor coil resistance

Approx. 2 - 5 -

SPECIAL TOOL

Tool Number Name Use

MB991519 Alternator test

harness

Checking the alternator (S terminal voltage)

16-4

ENGINE ELECTRICAL -

Charging System

ON-VEHICLE SERVICE

ALTERNATOR OUTPUT LINE VOLTAGE DROP TEST

Alternator

Voltmeter

Terminal B

This test determines whether the wiring from the alternator “B” terminal to the battery (+) terminal (including the fusible line) is in a good condition or not.

1. Always be sure to check the following before the test.

Alternator installation

Alternator drive belt tension

Fusible link

Abnormal noise from the alternator while the engine is running

2. Turn the ignition switch off.

3. Disconnect the negative battery cable.

4. Disconnect the alternator output wire from the alternator “B” terminal and connect a DC test ammeter with a range of 0 - 100 A in series between the “B” terminal and the disconnected

Ammeter

Battery

output wire. (Connect the (+) lead of the ammeter to the “B” terminal, and then connect the (- ) lead of the ammeter to the disconnected output wire.)

NOTE An inductive-type ammeter which enables measurements to be taken without disconnecting the alternator output wire should be recommended. Using this equipment will lessen the possibility of a voltage drop caused by a loose “B” terminal connection.

5. Connect a digital-type voltmeter between the alternator “B” terminal and the battery (+) terminal. (Connect the (+) lead of the voltmeter to the “B” terminal and the connect the ( - ) lead of the voltmeter to the battery (+) cable.)

ENGINE ELECTRICAL -

Charging System

16-5

6. Reconnect the negative battery cable.

7. Connect a tachometer or the MUT-II.

8. Leave the hood open.

9. Start the engine.

10. With the engine running at 2,500 r/min, turn the headlamps and other lamps on a n d off to adjust the alternator load so that the value displayed on the ammeter is slightly above 30 A. Adjust the engine speed by gradually decreasing it until the value displayed on th e ammeter is 30 A. Take a reading of the value displayed on the voltmeter at this time.

Limit: max. 0.3 V

NOTE When the alternator output is high and the value displayed on the ammeter does not decrease until 30 A, set the value to 40 A. Read the value displayed on the voltmeter at this time. When the value range is 40 A, the limit is max.

0.4 V.

OUTPUT CURRENT TEST

11. If the value displayed on the voltmeter is above the limit value, there is probably a malfunction in the alternator output wire, so check the wiring between the alternator “B” terminal and the battery (+) terminal (including fusible link). If a terminal is not sufficiently tight or if the harness has become discolored due to overheating, repair and then test again.

12. After the test, run the engine at idle.

13. Turn off all lamps and the ignition switch.

14. Remove the tachometer or the MUT-II.

15. Disconnect the negative battery cable.

16. Disconnect the ammeter an d voltmeter.

17. Connect the alternator output wire to the alternator “B” terminal.

18. Connect the negative battery cable.

Ignition switch

Battery

Charging warning lamp

Alternator relay

Voltmeter

Ammeter

+-+-

Engine

-ECU

Load

Alternator

16-6

ENGINE ELECTRICAL -

Charging System

This test determines whether the alternator output current is normal.

1. Before the test, always be sure to check the following.

D Alternator installation D Battery

NOTE The battery should be slightly discharged. The load needed by a fully-charged battery is insufficient for an accurate test.

D Alternator drive belt tension D Fusible link D Abnormal noise from the alternator while

the engine is running.

2. Turn the ignition switch off.

3. Disconnect the negative battery cable.

4. Disconnect the alternator output wire from the alternator “B” terminal. Connect a DC test ammeter with a range of 0 - 100 A in series between the “B” terminal and the disconnected output wire. (Connect the (+) lead of the ammeter to the “B” terminal. Connect the ( - ) lead of the ammeter to the disconnected output wire.)

Caution Never use clips but tighten bolts and nuts to connect the line. Otherwise loose connections (e.g. using clips) will lead to a serious accident because of high current.

NOTE An inductive-type ammeter which enables measurements to be taken without disconnecting the alternator output wire should be recommended.

5. Connect a voltmeter with a range of 0- 20 V between the alternator “B” terminal and the earth. (Connect the (+) lead of the voltmeter to the “B” terminal, and then connect the (- ) lead of the voltmeter to the earth.)

6. Connect the negative battery cable.

7. Connect a tachometer or the MUT-II.

8. Leave the hood open.

9. Check that the reading on the voltmeter is equal to the battery voltage.

NOTE If the voltage is 0 V, the cause is probably an open circuit in the wire or fusible link between the alternator “B” terminal and the battery (+) terminal.

10. Turn the light switch on to turn on headlamps and then start the engine.

11. Immediately after setting the headlamps to high beam and turning the heater blower switch to the high revolution position, increase the engine speed to 2,500 r/min and read the maximum current output value displayed on the ammeter.

Limit: 70% of normal current output

NOTE D For the nominal current output, refer to the

Alternator Specifications.

D Because the current from the battery will

soon drop after the engine is started, the above step should be carried out as quickly as possible in order to obtain the maximum current output value.

D The current output value will depend on

the electrical load and the temperature of the alternator body.

D If the electrical load is small while testing,

the specified level of current may not be output even though the alternator is normal. In such cases, increase the electrical load by leaving the headlamps turned on for some time to discharge the battery or by using the lighting system in another vehicle, and then test again.

D The specified level of current also may not

be output if the temperature of the alternator body or the ambient temperature is too high. In such cases, cool the alternator and then test again.

12. The reading on the ammeter should be above the limit value. If the reading is below t he limit value and the alternator output wire is normal, remove the alternator from the engine and check the alternator.

13. Run the engine at idle after the test.

14. Turn the ignition switch off.

15. Remove the tachometer or the MUT-II.

16. Disconnect the negative battery cable.

17. Disconnect the ammeter an d voltmeter.

18. Connect the alternator output wire to the alternator “B” terminal.

19. Connect the negative battery cable.

ENGINE ELECTRICAL -

REGULATED VOLTAGE TEST

Ignition switch

Charging warning lamp

Alternator relay

EngineECU

MB991519

Charging System

Alternator

L S

Yellow

Ammeter

16-7

Load

Battery

Voltmeter

This test determines whether the voltage regulator is correctly controlling the alternator output voltage.

1. Always be sure to check the following before the test.

Alternator installation

Check that the battery installed in the vehicle is fully charged.

Alternator drive belt tension

Fusible link

Abnormal noise from the alternator while the engine is running

2. Turn the ignition switch off.

3. Disconnect the negative battery cable.

4. Use the special tool (Alternator test harness: MB991519) to connect a digital voltmeter between the alternator S terminal and earth. (Connect the (+) lead of the voltmeter to the ”S” terminal, and then connect the (-) lead of the voltmeter to a secure earth or to the battery (-) terminal.)

5. Disconnect the alternator output wire from the alternator “B” terminal.

6. Connect a DC test ammeter with a range of 0 - 100 A in series between the “B” terminal and the disconnected output wire. (Connect the (+) lead of the ammeter to the “B” terminal. Connect the ( - ) lead of the ammeter to the disconnected output wire.)

7. Reconnect the negative battery cable.

8. Connect a tachometer or the MUT-II.

9. Turn the ignition switch to the ON position a nd check that the reading on the voltmeter is equal to the battery voltage.

NOTE If the voltage is 0 V, the cause is probably an open circuit in the wire or fusible link between the alternator “S” terminal and the battery (+) terminal.

10. Turn all lamps and accessories off.

11. Start the engine.

12. Increase the engine speed to 2,500 r/min.

13. Read the value displayed on the voltmeter when the alternator output current alternator becomes 10 A or less.

16-8

ENGINE ELECTRICAL -

Charging System

14. If the voltage reading conforms to th e value in the voltage regulation, then the voltage regulator is operating normally. If the voltage is not within the standard value, there is a malfunction of the voltage regulator or of the alternator.

15. After the test, lower the engine speed to the idle speed.

16. Turn the ignition switch off.

Voltage Regulation Table Standard value:

Inspection terminal Voltage regulator ambient temperature_C Voltage V

Terminal “S” -20 14.2- 15.4

20 13.9- 14.9

60 13.4- 14.6

80 13.1- 14.5

17. Remove the tachometer or the MUT-II.

18. Disconnect the negative battery cable.

19. Disconnect the ammeter an d voltmeter.

20. Connect the alternator output wire to the alternator “B” terminal.

21. Remove the special tool, and return the connector to the original condition.

22. Connect the negative battery cable.

ENGINE ELECTRICAL -

Charging System

16-9

WAVEFORM CHECK USING AN ANALYZER

MEASUREMENT METHOD

Alternator

Special patterns pickup

Analyzer

Connect the analyzer special patterns pick-up to th e alternator B terminal.

B terminal

STANDARD WAVEFORM Observation Conditions

FUNCTION SPECIAL PATTERNS

PATTERN HEIGHT VARIABLE

VARIABLE knob Adjust while viewing the waveform.

PATTERN SELECTOR RASTER

Engine speed Curb idle speed

Voltage at alternator B terminal

0.4

0.2

- 0.2

- 0.4

Time

NOTE The voltage waveform of the alternator B terminal can undulate as shown at left. This waveform is produced when the regulator operates according to fluctuations in the alternator load (current), and is normal for the alternator. In addition, when the voltage waveform reaches an excessively high value (approx. 2 V or higher at idle), it often indicates an open circuit due to a brown fuse between alternator B terminal and battery, but not a defective alternator.

16-10

ENGINE ELECTRICAL -

Charging System

EXAMPLES OF ABNORMAL WAVEFORMS

NOTE

1. The size of the waveform patterns differs largely, depending on the adjustment of the variable knob on the analyzer.

2. Identification of abnormal waveforms is easier when there is a large output current (regulator is not operating). (Waveforms can be observed when the headlamps are illuminated.)

3. Check the conditions of the charging warning lamp (illuminated/not illuminated). Also, check the charging system totally.

Abnormal waveforms Problem

cause

Open diode

Short in diode

Broken wire in stator coil

Example 1

Example 2

Example 3

Abnormal waveforms Problem

cause

Short in stator coil

Open supplementary diode

Example 4

Example 5

At this time, the charging warning lamp is illuminated.

Alternator relay

ALTERNATOR RELAY CONTINUITY CHECK

1. Remove the alternator relay from the relay box inside the engine compartment.

2. Set the analogue-type circuit tester to the W range and check that there is continuity when the (+) terminal of the tester is connected to terminal 2 of the alternator relay and the ( - ) terminal is connected to terminal 4.

3. Next, check that there is no continuity when the (+) terminal is connected to terminal 4 and the ( - ) terminal is connected to terminal 2.

4. If defect is found in steps 2 and 3 above, replace the alternator relay.

ENGINE ELECTRICAL -

Charging System

16-11

ALTERNATOR

REMOVAL AND INSTALLATION

Pre-removal Operation

Under Cover and Side Cover (R.H. side) Removal

<4G6>

20 - 25 Nm

24 Nm

16100140286

Post-installation Operation

D Drive Belt Tension Adjustment

(Refer to GROUP 11 - On-vehicle Service.)

D Under Cover and Side Cover (R.H. side) Installation

<4G9>

49 Nm

20 - 25 Nm

49 Nm

44 Nm

Removal steps

1. Drive belt (Power steering, A/C)

2. Drive belt (Alternator)

3. Alternator connector

4. Alternator

5. Alternator brace

16-12

ENGINE ELECTRICAL -

DISASSEMBLY AND REASSEMBLY

Charging System

Disassembly steps

AA" 1. Front bracket assembly AB" 2. Alternator pulley

AB" 3. Rotor

4. Rear bearing

5. Bearing retainer

6. Front bearing

7. Front bracket

AC" 8. Startor

9. Plate

AC""AA 10. Regulator assembly

11. Brush

12. Slinger

13. Rectifier

14. Rear bracket

ENGINE ELECTRICAL -

DISASSEMBLY SERVICE POINTS

AA"

Insert flat tip screwdrivers or the like in the clearance between the front bracket assembly and stator core, to pry open and separate the stator and front bracket.

Caution Do not insert the screwdriver too far, or the stator coil gets damaged.

FRONT BRACKET ASSEMBLY REMOVAL

Charging System

16-13

Soldered

AB"

Face the pulley side upward, fix the rotor with a work bench and remove the pulley.

Caution Use care not to damage the rotor.

AC"

1. Unsolder the stator with a soldering iron (180 to 250W).

2. When removing the rectifier from the regulator assembly,

ALTERNATOR PULLEY REMOVAL

STATOR/REGULATOR ASSEMBLY REMOVAL

Complete this work within four seconds not to transfer heat to the diode.

remove the soldered sections of the rectifier.

Caution (1) Use careto makesure thatthe heatof thesoldering

iron is not transmitted to the diodes for a long period.

(2) Use care that no undue force is exerted to the

lead wires of the diodes.

16-14

ENGINE ELECTRICAL -

Wire

Rear bracket

Brush

Wire

Charging System

REASSEMBLY SERVICE POINTS

"AA

After installing the regulator assembly, insert a wire into the hole provided on the rear bracket while pressing in the brush to fix the brush.

NOTE The brush is fixed when a wire is inserted, making rotor installation easier.

REGULATOR ASSEMBLY INSTALLATION

Wire

"BA

ROTOR INSTALLATION

After installing the rotor, remove the wire used to fix the brush.

INSPECTION

16100170216

ROTOR CHECK

1. Check the continuity between the rotor coil slip rings, and replace the rotor if the resistance value is not at the standard value.

Standard value: 3 - 5

2. Check the continuity between the slip ring an d core, and if there is continuity, replace the rotor.

ENGINE ELECTRICAL -

STATOR CHECK

1. Check the continuity between the coil leads, and if there is continuity, replace the stator.

2. Check the continuity between the coil and core, and if there is continuity, replace the stator.

Charging System

16-15

RECTIFIER CHECK

1. Inspect the (+) heat sink by checking the continuity between the (+) heat sink and stator coil lead wire connection terminal using a tester probe. If there is a continuity at both, the diode is short circuited, so replace the rectifier.

2. Inspect the ( - ) heat sink by checking the continuity between the ( - ) heat sink and stator coil lead wire connection terminal using a tester probe. If there is a continuity at both, the diode is short circuited, so replace the rectifier.

3. Check the diode trio by connecting an ohmmeter to both ends of each diode and check the continuity of the three diodes. If there is a continuity at both ends, or if there is no continuity, the diode is damaged so replace the rectifier.

16-16

Protrusion length

ENGINE ELECTRICAL -

BRUSH CHECK

1. Measure the length of the brush protrusion shown in the illustration, and replace the brush if th e measured value is below the limit value.

Limit: 2 mm or less

Charging System

Soldered

2. The brush can be removed if the solder of the brush lead wire is removed.

3. When installing a new brush, insert the brush into the holder as shown in the illustration, and then solder the lead wires.

ENGINE ELECTRICAL -

STARTING SYSTEM

GENERAL INFORMATION

Starting System

16-17

If the ignition switch is turned to the ”START” position, current flows in the pull-in and holding coils provided inside magnetic switch, attracting the plunger. When the plunger is attracted, the lever connected to the plunger is actuated to engage the starter clutch. On the other hand, attracting the plunger will turn on the magnetic switch, allowing the B terminal

SYSTEM DIAGRAM

Ignition switch

Battery

Brush

and M terminal to conduct. Thus, current flows to engage the starter motor. When the ignition switch is returned to t he “ON” position after starting the engine, the starter clutch is disengaged from the ring gear. An overrunning clutch is provided between the pinion and the armature shaft, to prevent damage to the starter.

Holding coil

Pull-in coil

Armature

Yoke

Plunger

Lever

Over-running clutch

Pinion shaft

STARTER MOTOR SPECIFICATIONS

Items 4G9 4G6

Type Reduction drive with planetary gear Reduction drive with planetary gear

Rated output kW/V 1.2/12 1.4/12

No. of pinion teeth 8 8

SERVICE SPECIFICATIONS

Items Standard value Limit

Pinion gap mm 0.5 - 2.0 -

Commutator outer diameter mm 29.4 28.8

Commutator runout mm 0.05 0.1

Commutator undercut mm 0.5 0.2

16-18

ENGINE ELECTRICAL -

Starting System

<4G9>

<4G6>

Battery

Switch

Wire

Switch

Wire

Battery

STARTER MOTOR

INSPECTION

PINION GAP ADJUSTMENT

1. Disconnect field coil wire from M-terminal of magnetic switch.

2. Connect a 12V battery between S-terminal and M-terminal.

3. Set switch to “ON”, and pinion will move out.

Caution This test must be performed quickly (in less than 10 seconds) to prevent coil from burning.

4. Check pinion to stopper clearance (pinion gap) with a thickness gauge.

Pinion

Pinion gap: 0.5 - 2.0 mm

Stopper

Pinion gap

5. If pinion gap is out of specification, adjust by adding or removing gaskets between magnetic switch and front bracket.

ENGINE ELECTRICAL -

Starting System

16-19

<4G9>

<4G6>

<4G9>

<4G6>

Battery

MAGNETIC SWITCH PULL-IN TEST

Battery

1. Disconnect field coil wire from M-terminal of magnetic switch.

2. Connect a 12V battery between S-terminal and M-terminal.

Caution

Wire

This test must be performed quickly (in less than 10 seconds) to prevent coil from burning.

3. If pinion moves out, then pull-in coil is good. If it doesn’t, replace magnetic switch.

Wire

MAGNETIC SWITCH HOLD-IN TEST

1. Disconnect field coil wire from M-terminal of magnetic switch.

Battery

2. Connect a 12V battery between S-terminal and body.

Caution This test must be performed quickly (in less than

Wire

10 seconds) to prevent coil from burning.

3. Manually pull ou t the pinion as far as the pinion stopper position.

4. If pinion remains out, everything is in order. If pinion moves in, hold-in circuit is open. Replace magnetic switch.

Battery

Wire

16-20

ENGINE ELECTRICAL -

Starting System

<4G9>

Starter motor

<4G6>

Starter motor

<4G9>

Carbon-pile rheostat

Ammeter

FREE RUNNING TEST

1. Place starter motor in a vise equipped with soft jaws and connect a fully-charged 12-volt battery to starter motor as follows:

2. Connect a test ammeter (100-ampere scale) and carbon pile rheostat in series with battery positive post and starter motor terminal.

3. Connect a voltmeter (15-volt scale) across starter motor.

Voltmeter

Battery

4. Rotate carbon pile to full-resistance position.

Carbon-pile rheostat

5. Connect battery cable from battery negative post to starter motor body.

6. Adjust the rheostat until the battery voltage shown by

Ammeter

the voltmeter is 11 V.

7. Confirm that the maximum amperage is within the

Battery

Voltmeter

specifications and that the starter motor turns smoothly and freely.

Current: max. 90 Amps

MAGNETIC SWITCH RETURN TEST

1. Disconnect field coil wire from M-terminal of magnetic switch.

Battery

2. Connect a 12V battery between M-terminal and body.

Caution This test must be performed quickly (in less than

Wire

10 seconds) to prevent coil from burning.

3. Pull pinion out and release. If pinion quickly returns to its original position, everything is in order. If it doesn’t, replace magnetic switch.

<4G6>

Battery

Caution Be careful not to get your fingers caught when pulling out the pinion.

Wire

ENGINE ELECTRICAL -

DISASSEMBLY AND REASSEMBLY

Starting System

16-21

Disassembly steps

1. Screw

AA" 2. Magnetic switch

3. Screw

4. Through bolt

5. Rear bracket

6. Brush holder

7. Brush

8. Rear bearing

AB" 9. Armature

10. Yoke assembly

AB" 11. Ball

12. Packing A

13. Packing B

14. Plate

15. Planetary gear

16. Lever

AC""AA 17. Snap ring AC""AA 18. Stop ring

19. Overrunning clutch

20. Internal gear

21. Planetary gear holder

22. Front bracket

16-22

ENGINE ELECTRICAL -

Starting System

Magnetic switch

Stop ring

S terminal

M terminal

Field coil wire

Socket

Pinion gear

DISASSEMBLY SERVICE POINTS

AA"

AB"

AC"

1. Using an appropriate wrench socket, push the stop ring

MAGNETIC SWITCH REMOVAL

Disconnect the field coil wire from terminal M of the magnetic switch.

ARMATURE AND BALL REMOVAL

When removing the armature, do not lose the ball placed at the end as a bearing.

SNAP RING/STOP RING REMOVAL

toward the overrunning clutch.

Snap ring

Pinion gear

Overrunning clutch

Snap ring pliers

2. Remove the snap ring with snap ring pliers and then remove the stop ring and overrunning clutch.

STARTER MOTOR PARTS CLEANING

1. Do not immerse the parts in cleaning solvent. Immersing the yoke and field coil assembly and/or armature will damage insulation. Wipe these parts with a cloth only.

2. Do not immerse the drive unit in cleaning solvent. The overrunning clutch is pre-lubricated at the factory and solvent will wash lubrication from clutch.

3. The drive unit may be cleaned with a brush moistened with cleaning solvent and wiped dry with a cloth.

Stop ring

Overrunning clutch

Snap ring

ENGINE ELECTRICAL -

REASSEMBLY SERVICE POINTS

"AA

Using an appropriate tool, pull the stop ring over the snap ring.

Stop ring

STOP RING/SNAP RING INSTALLATION

INSPECTION

COMMUTATOR

1. Place the armature in a pair of “V” blocks and check the runout with a dial indicator.

Standard value: 0.05 mm Limit: 0.1 mm

Starting System

16-23

Segment

Undercut

Mica

Free

2. Measure the commutator outer diameter.

Standard value: 29.4 mm Limit: 28.8 mm

3. Check the undercut depth between segments.

Standard value: 0.5 mm Limit: 0.2 mm

OVERRUNNING CLUTCH

1. Check that the pinion locks when it is turned counterclockwise and moves smoothly when it is turned clockwise.

2. Check the pinion for wear or damage.

Lock

16-24

ENGINE ELECTRICAL -

BRUSH

1. Check the brush for roughness of the surface that contacts the commutator and check the brush length.

Limit: Wear limit line

2. In case the contacting surface has been corrected or

Wear limit line

the brush has been replaced, correct the contacting surface by winding sandpaper around the commutator.

Starting System

Growler

ARMATURE COIL SHORT-CIRCUIT TEST

1. Place armature in a growler.

2. Hold a thin steel blade parallel and just above while rotating armature slowly in growler. A shorted armature will cause blade to vibrate and be attracted to the core. Replace shorted armature.

Caution Clean the armature surface thoroughly before checking.

3. Check the insulation between each commutator segment and armature coil core. If there is no continuity, the insulation is in order.

ARMATURE COIL OPEN-CIRCUIT INSPECTION

Check the continuity between segments. If there is continuity, the coil is in order.

ENGINE ELECTRICAL -

IGNITION SYSTEM

GENERAL INFORMATION

Ignition System

16-25

This system is equipped with four ignition coils with built-in power transistors for each of the cylinders. Interruption of the primary current flowing in the primary side of an ignition coil generates a high voltage in the secondary side of the ignition coil. The high voltage thus generated is applied to the spark plugs to generate sparks. The engine-ECU turns the power transistors inside the ignition coils alternately on and off. This causes the primary currents in the ignition coils to be alternately interrupted and allowed to flow to fire the cylinders in the order 1 - 3 - 4 - 2.

SYSTEM DIAGRAM

Air flow sensor

Barometric pressure sensor

Intake air temperature sensor

Engine coolant temperature sensor

Accelerator pedal position switch <4G6>

Camshaft position sensor

Crank angle sensor

Ignition switch-ST

Detonation sensor

Vehicle speed sensor Inhibitor switch <A/T>

EngineECU

The engine-ECU determines which ignition coil should be controlled by means of the signals from the camshaft position sensor and the crank angle sensor. It also detects th e crankshaft position, in order to provide ignition at the most appropriate timing in response to the engine operation conditions. When the engine is cold or running at high altitudes, the ignition timing is slightly advanced to provide optimum performance. Furthermore, if knocking occurs, th e ignition timing is gradually retarded until knocking ceases.

Ignition switch

Ignition coil

Battery

Spark plug

To tachometer

Cylinder No.

IGNITION COIL SPECIFICATION

Items Specification

Type Molded 4-coil

SPARK PLUG SPECIFICATION

Items 4G6 4G9

NGK IZFR5B IZFR6B

16-26

ENGINE ELECTRICAL -

Ignition System

SERVICE SPECIFICATIONS

SPARK PLUG

Items Standard value Limit

Spark plug gap mm 0.5 - 0.6 0.75

Spark plug insulation resistance MW - 1

ON-VEHICLE SERVICE

1.5 V

IGNITION COIL (WITH BUILT-IN POWER TRANSISTOR) CHECK

PRIMARY COIL AND POWER TRANSISTOR CONTINUITY CHECK

NOTE

1. An analogue-type circuit tester should be used.

2. Connect the negative ( - ) prove of the circuit tester to terminal 1.

Caution This test must be performed quickly (in less than 10 seconds) to prevent coil from burning and power transistor from breakage.

Voltage: 1.5V

When current is flowing

When current is not flowing

SECONDARY COIL CHECK

NOTE

It is impossible to check the secondary coil through the continuity check as a diode is integrated in the secondary coil circuit of this ignition coil. So, check the secondary coil in the following procedure.

1. Disconnect the ignition coil connector.

2. Remove the ignition coil and install a new spark plug to the ignition coil.

3. Connect the ignition coil connector.

4. Earth the side electrode of the spark plug and crank the engine.

Terminal No.

1 2 3

ENGINE ELECTRICAL -

5. Check that spark is produced between the electrodes of the spark plug.

6. If no spark is produced, replace the ignition coil with a new one and recheck.

7. If spark is produced with the new ignition coil, replace the old one as it is faulty. If no spark is produced again, the ignition circuit is suspected as faulty. Check theignition circuit.

SPARK PLUG CHECK AND CLEANING

Caution

1. The spark plug gap for iridium plugs should not be adjusted.

2. Cleaning iridium plugs may result in damage to the iridium tip. Therefore, if cleaning is necessary because the plug is sooty, use a plug cleaner, and do not clean the plug for more than 20 seconds in order to preserve the electrodes. A wire brush should never be used.

3. The spark plugs in GDI engines are special iridium plugs in which the electrodes can become black even when the plugs are working normally. Carbon which may become deposited on these plugs burns off more readily than with conventional plugs, and so should not cause any problems with spark plug performance. Judgement of whether a spark plug is operating normally or not should be made by checking the insulation resistance.

Ignition System

16-27

1. Remove the ignition coils.

2. Remove the spark plugs.

3. Check the spark plug gap. Replace the spark plug if the gap exceeds the limit.

Limit: 0.75 mm Standard value: 0.5 - 0.6 mm

4. Measure the spark plug insulation resistance. Replace the spark plug if the measured value is lower than the limit value.

Limit: 1 M

5. Clean the spark plug holes.

6. Install the spark plugs.

7. Install the ignition coils.

16-28

ENGINE ELECTRICAL -

CAMSHAFT POSITION SENSOR CHECK

Refer to GROUP 13A - Troubleshooting <4G6> or GROUP 13B - Troubleshooting <4G9>.

CRANK ANGLE SENSOR CHECK

Refer to GROUP 13A - Troubleshooting <4G6> or GROUP 13B - Troubleshooting <4G9>.

DETONATION SENSOR CHECK

Check the detonation sensor circuit if self-diagnosis code, No. 31 is shown.

NOTE For information concerning the self-diagnosis codes, refer to GROUP 13A - Troubleshooting <4G6> or GROUP 13B

- Troubleshooting <4G9>.

Ignition System

ENGINE ELECTRICAL -

Ignition System

16-29

IGNITION COIL

REMOVAL AND INSTALLATION

Pre-removal and Post-installation Operation

Engine Cover Removal and Installation

10 Nm

25 Nm

16300320174

Removal steps

1. Ignition coil connector

2. Ignition coil

3. Spark plug

CRANK ANGLE SENSOR

REMOVAL AND INSTALLATION

Pre-removal and Post-installation Operation

D Timing Belt Removal and Installation <4G6>

(Refer to GROUP 11A.)

<4G6> <4G9>

10 - 12 Nm

Crank angle sensor

16300350036

D Timing Belt Front Lower Cover Removal and

Installation <4G9> (Refer to GROUP 11B.)

10 - 12 Nm

Crank angle sensor

9Nm

16-30

ENGINE ELECTRICAL -

Ignition System

CAMSHAFT POSITION SENSOR

REMOVAL AND INSTALLATION

Pre-removal and Post-installation Operation

Engine Cover Removal and Installation

<4G6>

9Nm

Camshaft position sensor

<4G9>

16300340026

9Nm

Camshaft position sensor

ENGINE ELECTRICAL -

Ignition System

16-31

DETONATION SENSOR

REMOVAL AND INSTALLATION

Caution Do not subject the detonation sensor to any shocks.

Pre-removal and Post-installation Operation

D Engine Cover Removal and Installation D Air Cleaner Assembly Removal and Installation

<4G6>

D Intake Manifold Stay Removal and Installation

16300280144

(Refer to GROUP 15.)

20 - 25 Nm

<4G9>

AA""AA

1. Detonation sensor

10 - 12 Nm

REMOVAL SERVICE POINT

AA"

DETONATION SENSOR REMOVAL

20 - 25 Nm

MD998773

INSTALLATION SERVICE POINT

"AA

DETONATION SENSOR INSTALLATION

NOTES

Mitsubishi ENGINE ELECTRICAL SPECIFICATIONS

Specifications and Main Features

Frequently Asked Questions

User Manual

CHARGING SYSTEM

GENERAL INFORMATION

SERVICE SPECIFICATIONS

SPECIAL TOOL

ON-VEHICLE SERVICE

ALTERNATOR

STARTING SYSTEM

GENERAL INFORMATION

SERVICE SPECIFICATIONS

STARTER MOTOR

IGNITION SYSTEM

GENERAL INFORMATION

SERVICE SPECIFICATIONS

ON-VEHICLE SERVICE

IGNITION COIL

CRANK ANGLE SENSOR

CAMSHAFT POSITION SENSOR

DETONATION SENSOR