Impco HHI Service Manual

2007-

2009

LPG

& Bi

2.0L

Service Manual

HHI

Emission Certified

-Fuel

System

Engine

Revision A/June, 2009

Table of Contents

General Information

................................

An overview

of this Service Manual

Maintenance

................................

General maintenance and maintenance interval information

LPG Fuel System

................................

An overview of the LPG fuel system and its components

LPG Fuel System Diagnosis

How to identify a general problem

LPG Symptom Diagnos

tics

How to correct a specific problem

Gasoline Fuel System

................................

An overview of the

Gasoline

Gasoline Fuel System Diagn

How to identify a general problem

Gasoline

Symptom Diagnostics

How to correct a specific problem

Electrical Section

................................

Diagnostic Scan Tool

................................

Using the DST for testing and trouble shooting

Wire Schematic

................................

Engine wiring schematic

Engine Wire Harness Repair

Repairing a wire harness on the vehicle

Diagnost

ic Trouble Codes (DTCs)

Application, schematic and DTC specific code information

................................

fuel system (bi-fuel models only)

and its components

osis................................

................................

with the Gasoline fuel system bi-

fuel

................................

with the Gasoline fuel system (bi-

fuel model

................................

...........................

................................

.....5

............... 11

....... 19

..................... 29

....................... 39

.............. 63

models only)

............... 71

s only)

....... 85

..... 121

................ 125

...... 129

Servicing the Fuel System

Step by step instructions on how

Definitions

................................

Definitions of phrases and acronyms used throughout this Service Manual

Tool Kit & Accessories

................................

Definitions of phrases and acronyms used throughout this Service Manual

Appendix

................................

Altitude vs. Barometric Pressure

................................

repair and/or replace fuel related c

omponents

................................

..............................

................................

& Ignition System Specifications

........................ 457

.................. 475

481

.................... 483

General Information

GENERAL INFORMATION

INTRODUCTION

This service manual supplement has been developed to provide the service technician with the basic understanding of the IMPCO certified fuel and emission systems for the

2.0L engine. This manual should be used in conjunction with the base engine manual and the OEM service manual when diagnosing fuel or electrical problems.

HOW TO IDENTIFY THE ENGINE YEAR

The 2.0L engine blocks have been stamped with a serial number. The number can be found on the left side of the top edge of the engine block near the exhaust manifold.

Engine Identification Number Table

SERVICING YOUR EMISSIONS CERTIFIED ENGINE

Any maintenance and repair should be performed by trained and experienced service technicians. Proper tools and equipment should be used to prevent injury to the servic-

ing technician and damage to the vehicle or components. Service repairs should always be performed in a safe environment and the technician should always wear protective clothing to prevent injury.

For parts or labor to be reimbursed under the IMPCO Technologies Inc. emission warranty, only work performed by IMPCO or OEM trained technicians using only IMPCO specified parts will qualify for reimbursement. Refer to the IMPCO Labor Time Guide for additional information.

For parts or labor not reimbursed under warranty, a repair shop or person of the owner’s choosing may maintain, replace, or repair emission-control devices and systems. It is highly recommended that any replacement parts used for maintenance or for the repair of emission control systems be new OEM replacement parts. The use of other than genuine IMPCO replacement parts may impair the effectiveness of emission control systems, therefore, the owner should assure that such parts are warranted by their manufacturer to be equivalent to genuine IMPCO OEM parts in performance and durability.

FUEL QUALITY

LPG

Note that LPG engines are designed to operate on HD–5 or HD–10 specification LPG fuel. Fuel other than HD–5 or HD–10 may cause harm to the engine’s emission control system and a warranty claim may be denied on this basis if operators can readily find the proper fuel*.

Use of any other fuel may result in your engine no longer operating in compliance with CARB or EPA emissions requirements.

*Not Applicable in the state of California.

GENERAL INFORMATION

Gasoline

IMPCO recommends the use of name brand high detergent gasoline. Gasoline is a mixture of many different hydrocarbons, including olefins, which are heavy, waxy compounds. Over time, these deposits can build up and clog the fuel injectors. The formation of these deposits is a normal consequence of engine operation, so detergents are added to high quality gasoline to help keep the injectors clean. The use of low quality low detergent gasoline may cause fuel injectors to fail. Fuel injector replacement or cleaning is expensive, and the cleaning procedure requires special equipment that may not be practical in the industrial lift truck market. Speak with your fuel supplier to verify that the fuel you are supplied contains the necessary fuel additives to keep your fuel system clean. IMPCO may deny emissions related warranty claims due to the use of low quality low detergent gasoline.

FUEL SYSTEM CAUTIONS

Do not smoke, carry lighted tobacco or use a lighted flame of any type when working on or near any fuel related component. Highly flammable air-fuel mixtures may be present and can be ignited causing personal injury

Do not allow LPG to contact the skin.

LPG is stored in the fuel tank as a liquid. When LPG contacts the atmosphere, it immediately expands into a gas, resulting in a refrigeration effect that can cause severe burns to the skin.

Do not allow LPG to accumulate in areas below ground level such as in a service pit or underground ventilation systems. LPG is heavier than air and can displace oxygen, creating a dangerous condition

Do not make repairs to the LPG fuel

system if you are not familiar with or trained to service LPG fuel system. Contact the dealer who sold you the vehicle to locate a repair facility with trained technicians to repair your fuel system

WARNINGS, CAUTIONS AND NOTES

This manual contains several different Warnings, Cautions, and Notes that must be observed to prevent personal injury and or damage to the vehicle, the fuel system or personal property.

A “WARNING“ is an advisement that by performing a process or procedure listed in this manual improperly may result in serious bodily injury, death and/or serious damage to the vehicle or property.

Typical Warning Label:

Failure to heed instructions could result in death, injury, or property damage.

A “CAUTION” label or statement is used when it has been determine that by performing a process or procedure defined in the manual improperly a less severe result may occur. It

GENERAL INFORMATION

could however, result in serious bodily injury, and or serious damage to the vehicle or property damage.

Less severe than WARNING but has the

potential to cause injury or damage. Also used to notify of situations that could lead to eventual failure, injury or damage.

This caution label may also appear in area of this manual that applies to service and repair procedures which could render the fuel and emissions control system non-compliant. In addition it may also be used to indicate a failure to observe which may influence the terms of the warranty.

An “IMPORTANT” statement generally denotes a situation that requires strict adherence to the assembly, tightening, or service procedure. Failure to observe this procedure could result in an unsafe condition or improper performance of the vehicle or a component.

A “NOTE” statement applies to a specific item or procedure that is to be followed during the servicing of the vehicle or its components.

PROPER USE OF THIS SERVICE MANUAL, TOOLS AND EQUIPMENT

To reduce the potential for injury to the technician or others and to reduce damage to the vehicle during service repairs the technician should observe the following steps:

 The service procedures defined in this

manual, when followed, have been found to be a safe and efficient process to repair the fuel system. In some cases special tools may be required to perform the necessary procedures to safely remove and replace a failed component.

 The installed IMPCO fuel system has

been certified with the Environmental Protection Agency (EPA) and the California Air Resources Board (CARB) and complies with the regulation in effect at the time of certification. When servicing the fuel and emission control system you should follow all the recommended service and repair procedures to insure the fuel and emissions system is operating as designed and certified. Purposely or knowingly defeating or disabling any part or the fuel and emission system may be in violation of the anti-tampering provision of the EPA’s Clean Air Act.

 Tools identified in this manual with the

prefix “J” or “BT” can be procured through SPX in Warren, Michigan.

 Tools identified in this manual with a prefix

“ITK” can be acquired through OEM Parts Distribution.

IMPORTANT It is important to remember that there may be a combination of Metric and Imperial fasteners used in the installation of the IMPCO fuel system. Check to insure proper fit when using a socket or wrench on any fastener to prevent damage to the component being removed or injury from “slipping off” the fastener.

The IMPCO fuels system utilizes fuel lines hoses with swivel connections which attach to fixed mating connectors. You should always use a wrench of the proper size on both the swivel and fixed fitting to prevent turning of the fixed fitting. Turning of the fixed fitting may cause a “twisting” or “kinking” of the hose and may result in a restriction of the fuel line or a leak.

GENERAL INFORMATION

Always leak check any fuel system connection after servicing! Use an electronic leak detector and/or a liquid leak detection solution. Failure to leak check could result in serious bodily injury, death, or serious property damage.

Maintenance

MAINTENANCE

The maintenance of an engine and related components are critical to its operating performance and lifespan. Industrial engines operate in environments that often include hot and cold temperatures and extreme dust. The recommended maintenance schedule is listed in this section, however, environmental operating conditions and additional installed equipment may require more frequent inspection and servicing. The owner and/or service agent should review the operating conditions of the equipment to determine the inspection and maintenance intervals.

When performing maintenance on the engine, turn the ignition OFF and disconnect the battery negative cable to avoid injury or damage to the engine.

The engine installed in this equipment uses a serpentine drive belt con

ﬁguration that drives the water pump, alternator and additional pumps or devices. It is important to note that the drive belt is an integral part of the cooling and charging system and should be inspected according to the maintenance schedule in this section. When inspecting the belts check for:

 Cracks  Chunking of the belt  Splits  Material hanging loose from the belt  Glazing, hardening

If any of these conditions exist the belt should be replaced with the recommended OEM replacement belt.

Alcohol or Methanol based anti-freeze or plain water are not recommended for use in the cooling system at anytime.

SERPENTINE BELT SYSTEM

Serpentine belts utilize a spring-loaded tensioner to keep the belt properly adjusted. Serpentine belts should be checked according to the maintenance schedule in this section.

IMPORTANT: The use of “belt dressing” or “anti-slipping agents” on belts is not recommended.

COOLING SYSTEM

It is important that the cooling system of the engine be maintained properly to ensure proper performance and longevity.

Do not remove the cooling system pressure cap (radiator cap) when the engine is hot. Allow the engine to cool and then remove the cap slowly to allow pressure to vent. Hot coolant under pressure may discharge violently.

Note that the LPG vaporizer is connected to the cooling system and the fuel system may be adversely affected by low coolant levels and restricted or plugged radiator cores. Therefore, the cooling system must be maintained according to the recommend maintenance schedule in this section and also include:

 The regular removal of dust, dirt and debris

from the radiator core and fan shroud.

 Inspection of coolant hoses and components

for leaks, especially at the radiator hose connections. Tighten hose clamps if necessary.

 Check radiator hoses for swelling, separation,

hardening, cracks or any type of deterioration.

If any of these conditions exist the hose

should be replaced with a recommended OEM replacement part.

 Inspect the radiator cap to ensure proper seal-

ing.

COOLANT

Check coolant level in coolant recovery tank and add coolant as required. Add 50/50 mixture of

ethylene glycol antifreeze and distilled water or coolant per engine manufacturer’s instructions. Do not add plain water. Replace coolant per the recommended schedule.

IMPORTANT: The manufacturers of the engine and fuel system do not recommend the use of “stop leak” additives to repair leaks in the cooling system. If leaks are present the radiator should be removed and repaired or replaced.

ENGINE ELECTRICAL SYSTEM MAINTNANCE

The engine’s electrical system incorporates computers to control various related components. The electrical system connections and ground circuits require good connections. Follow the recommended maintenance schedule in this section to maintain optimum performance. When inspecting the electrical system check the following:

 Check Positive and Negative cables for corro-

sion, rubbing, chafing, burning and to ensure tight connections at both ends.

 Check battery for cracks or damage to the

case and replace if necessary.

 Inspect engine wire harness for rubbing, chaf-

ing, pinching, burning, and cracks or breaks in the wiring.

 Verify that engine harness connectors are cor-

rectly locked in by pushing in and then pulling the connector halves outward.

 Inspect primary ignition coil wires for harden-

ing, cracking, arcing, chafing, burning, separation, split boot covers.

 Check spark plug wires for hardening, crack-

ing, chafing, arcing or burning, separation, and split boot covers.

 Replace spark plugs at the required intervals

per the recommended maintenance schedule.

 Verify that all electrical components are se-

curely mounted to the engine or chassis.

 Verify that any additional electrical services

installed by the owner are properly installed in the system.

 Verify that the MIL, charging, and oil pressure

lights illuminate momentarily during engine start.

ENGINE CRANKCASE OIL

OIL RECOMMENDATION

Select an engine oil that will best match the prevailing daytime temperature:

Motor oils meeting this spec receive the API (American Petroleum Institute) starburst symbol:

The recommended API classification: Above SG.

The oil capacity for the 2.0L engine including a new filter is 1.1 gallons (4.0L)

IMPORTANT:

Oils recommended by the engine manufacturer already contain a balanced additive treatment. Oils containing “solid” additives, non-detergent oils, or low quality oils are not recommended by the engine manufacturer. The supplemental additives added to the engine oil are not necessary and may be harmful. The engine and fuel system

supplier do not review, approve or recommend such products.

SYNTHETIC OILS

Synthetic oils have been available for use in industrial engines for a relatively long period of time and may offer advantages in cold and hot temperatures. However, it is not known if synthetic oils provide operational or economic bene

ﬁts over conventional petroleum-based oils in industrial engines. Use of synthetic oils does not permit the extension of oil change intervals.

CHECKING/FILLING ENGINE OIL LEVEL

IMPORTANT: Care must be taken when checking engine oil level. Oil level must be maintained between the “ADD” mark and the “FULL” mark on the dipstick. To ensure that you are not getting a false reading, make sure the following steps are taken before checking the oil level.

1. Stop engine.

2. Allow approximately five minutes for the oil to

drain back into the oil pan.

3. Remove the dipstick. Wipe with a clean cloth

or paper towel and reinstall. Push the dipstick all the way into the dipstick tube.

4. Remove the dipstick and note the amount of

oil on the dipstick. The oil level must be between the “FULL” and “ADD” marks.

Figure 2 Engine Oil Dip tick (Typical)

5. If the oil level is below the “ADD” mark reinstall

the dipstick into the dipstick tube and proceed to Step 6.

6. Remove the oil

ﬁller cap from the valve cover.

7. Add the required amount of oil to bring the

level up to, but not over, the “FULL” mark on the dipstick Reinstall the oil

ﬁller cap to the

valve rocker arm cover and wipe any excess oil clean.

CHANGING THE ENGINE OIL

IMPORTANT:

When changing the oil, always change the oil

ﬁlter.

1. Start the engine and run until it reaches normal operating temperature.

An overfilled crankcase (oil level being too high) can cause an oil leak, a fluctuation or drop in oil pressure. When overfilled, the engine crankshafts splash and agitate the oil, causing it to aerate or foam.

IMPORTANT:

Change oil when engine is warm and the old oil flows more freely.

2. Stop engine

IMPORTANT:

Engine oil will be hot. Use protective gloves to prevent burns. Engine oil contains chemicals which may be harmful to your health. Avoid skin contact.

3. Remove drain plug and allow the oil to drain.

4. Remove and discard oil

ﬁlter and its sealing

ring.

5. Coat sealing ring on the new

ﬁlter with clean

engine oil, wipe the sealing surface on the

ﬁlter mounting surface to remove any dust, dirt

or debris. Tighten ﬁlter securely (follow ﬁlter manufacturer’s instructions). Do not over tigh-

ten.

6. Check sealing ring on drain plug for any damage, replace if necessary, wipe plug with clean rag, wipe pan sealing surface with clean rag and re-install plug into the pan. Tighten to

25.3-32.4 ft.lbs (34.3-44.1 Nm).

IMPORTANT: Always use a new drain plug gasket when changing the oil.

7. Fill crankcase with oil.

8. Start engine and check for oil leaks.

9. Dispose of oil and ﬁlter in a safe manner.

FUEL SYSTEM INSPECTION AND

MAINTENANCE

LPG FUEL SYSTEM

The LPG fuel system installed on this industrial engine has been designed to meet the emission standard applicable for the 2007-2009 model years. To ensure compliance to these standards, follow the recommended maintenance schedule contained in this section.

INSPECTION AND MAINTENANCE OF THE FUEL STORAGE CYLINDER

The fuel storage cylinder should be inspected daily or at the beginning of each operational shift for any leaks, external damage, adequate fuel supply and to ensure the manual service valve is open. Fuel storage cylinders should always be securely mounted, inspect the securing straps or retaining devices for damage ensure that all locking devices are closed and locked. Check to ensure that the fuel storage cylinder is positioned with the locating pin in the tank collar on all horizontally mounted cylinders this will ensure the proper function of the cylinder relief valve.

When refueling or exchanging the fuel cylinder, check the quick

ﬁll valve for thread damage. Also

verify O-ring is in place and inspect for cracks, chunking or separation. If damage to the o-ring is found, replace prior to

ﬁlling. Check the ser-

vice line quick coupler for any thread damage.

IMPORTANT:

When refueling the fuel cylinder, wipe both the female and male connection with a clean rag prior to

ﬁlling to prevent dust, dirt and debris from being

introduced to the fuel cylinder.

INSPECTION AND REPLACEMENT OF THE LPG FUEL FILTER

The LPG system on this emission certiﬁed engine utilizes an in-line replaceable fuel ﬁlter element. This element should be replaced, at the intervals speci

ﬁed in the recommended maintenance sche-

dule. When inspecting the fuel

ﬁlter check the

following:

 Check for leaks at the inlet and outlet ﬁttings,

using a soapy solution or an electronic leak detector and repair if necessary.

 Check to make sure ﬁlter is securely mounted.  Check ﬁlter housing for external damage or

distortion. If damaged replace fuel ﬁlter.

REPLACING THE LPG FUEL FILTER:

1. Move the equipment to a well ventilated area and verify that sparks, ignition and any heat sources are not present.

2. Start the engine.

3. Close the LPG tank valve.

4. When the engine stalls when it runs out of fuel, turn the ignition key to the OFF position and disconnect the battery negative cable.

IMPORTANT: A small amount of fuel may still be present in the fuel line. Use gloves and proper eye protection to prevent burns. If liquid fuel continues to

ﬂow

from the connections when removed, make sure the manual valve is fully closed.

5. Slowly loosen the inlet

ﬁtting and disconnect.

6. Slowly loosen the outlet ﬁtting and disconnect.

7. Remove the ﬁlter housing form the equipment.

8. Check for contamination.

9. Tap the opening of the

ﬁlter on a clean cloth.

10. Check for debris.

11. Check canister for proper mounting direction.

12. Reinstall the

ﬁlter housing to the equipment.

13. Tighten the inlet and outlet ﬁttings to specifica- tion.

14. Open the LPG tank valve.

IMPORTANT: The fuel cylinder manual valve contains an Excess Flow Check Valve. Open the valve slowly to prevent activating the Excess Flow Check Valve.

15. Check for leaks at the inlet and outlet

ﬁttings,

and the ﬁlter housing end connection using a soapy solution or an electronic leak detector, if leaks are detected make repairs.

ELECTRONIC PRESSURE REGULATOR (EPR) MAINTENANCE AND INSPECTION

IMPORTANT: The Electronic Pressure Regulator (EPR) components have been speci

ﬁcally designed and

calibrated to meet the fuel system requirements of the emission certi

ﬁed engine.

If the EPR fails to operate or develops a leak, it should be repaired or replaced with the OEM recommended replacement parts. When inspecting the regulator check for the following items:

 Check for any fuel leaks at the inlet and outlet

ﬁttings.

 Check for any fuel leaks in the regulator body.  Check the inlet and outlet ﬁttings of the coo-

lant supply lines for water leaks.

 Check the coolant supply lines for hardening,

cracking, chafing or splits. If any of these conditions exist replace coolant lines.

 Check coolant supply hose clamp connec-

tions, ensure they are tight.

 Check to ensure the EPR is securely mounted

and the mounting bolts are tight.

 Check EPR for external damage.  Check EPR electrical connection to ensure the

connector is seated and locked.

CHECKING/DRAINING OIL BUILD-UP IN THE ELECTRONIC PRESSURE REGULATOR

During the course of normal operation oil or “heavy ends” may build inside the secondary chamber of the Electronic Pressure Regulator (EPR). These oil and heavy ends may be a result of poor fuel quality, contamination of the fuel, or regional variation of the fuel make up. A significant build up of oil can affect the performance of the secondary diaphragm response. The Recommended Maintenance Schedule found in this section recommends that the oil be drained periodically. This is the minimum requirement to maintain the emission warranty. More frequent draining of the EPR is recommended for special situation where substandard fuel may be a problem. IMPCO recommends the EPR be drained at every engine oil change if contaminated or substandard fuel is suspected or known to have been used or in use with the emission complaint fuel system. This is known as special maintenance,

and failure to follow this recommendation may be used to deny a warranty claim.

IMPORTANT: Draining the regulator when the engine is warm will help the oils to

ﬂow freely from the regulator.

To drain the EPR, follow the steps below:

1. Move the equipment to a well ventilated area and ensure no external ignition sources are present.

2. Start the engine.

3. With the engine running close the LPG tank valve.

4. When the engine runs out of fuel turn OFF the key when the engine stops and disconnect the negative battery cable.

IMPORTANT: A small amount of fuel may still be present in the fuel line, use gloves to prevent burns, wear proper eye protection. If liquid fuels continues to

ﬂow

from the connections when loosened check to make sure the manual valve is fully closed.

5. Slowly loosen the inlet

ﬁtting and disconnect.

6. Loosen the hose clamp at the outlet hose ﬁtting and remove the hose.

7. Remove the Retaining Pin in the LPG Temperature Sensor and remove from the EPR

8. Remove the EPR mounting bolts.

9. Place a small receptacle in the engine compartment.

10. Rotate the EPR to 90° so that the outlet

ﬁtting

is pointing down into the receptacle and drain the EPR.

11. Inspect the secondary chamber for any large dried particles and remove.

12. Remove the receptacle and reinstall the EPR with the two retaining bolts and tighten to speci

ﬁcations.

13. Reinstall the outlet ﬁtting and secure with the previously removed Retaining pin.

14. Reconnect the electrical connector (push in until it clicks and securely locks), then pull on the connector to ensure it is locked.

15. Connect the vacuum line.

16. Reconnect the outlet hose and secure the hose clamp.

17. Reinstall the fuel inlet line and tighten connection to speci

ﬁcation.

18. Slowly open the LPG tank valve.

IMPORTANT: The fuel cylinder manual valve contains an Excess Flow Check Valve. Open the manual valve slowly to prevent activating the Excess Flow Check Valve.

19. Check for leaks at the inlet and outlet

ﬁttings

using a soapy solution or an electronic leak detector. If leaks are detected make repairs. Check coolant line connections to ensure no leaks are present.

20. Start engine recheck for leaks at the regulator.

21. Dispose of any drained material in safe and proper manner.

AIR FUEL MIXER/THROTTLE CONTROL DEVICE MAINTENANCE AND INSPECTION

IMPORTANT: The Air Fuel Mixer components have been speci

ﬁcally designed and calibrated to meet the

fuel system requirements of the emission certi

ﬁed

engine. The mixer should not be disassembled or rebuilt. If the mixer fails to operate or develops a leak the mixer should be replaced with the OEM recommended replacement parts.

When inspecting the mixer check for the following items:

 Leaks at the inlet ﬁtting.

 Fuel inlet hose for cracking, splitting or chaff-

ing, replace if any of these condition exist.

 Ensure the mixer is securely mounted.  Inspect air inlet hose connection and clamp.

Also inspect inlet hose for cracking, splitting or chafing. Replace if any of these conditions exist.

 Inspect Air cleaner element according to the

Recommended Maintenance Schedule found in this section.

 Check Fuel lines for cracking, splitting or chaf-

ing. Replace if any of these conditions exist.

 Verify Throttle Body return action to ensure

throttle shaft is not sticking. Repair if necessary.

 Check for leaks at the Throttle Body and in-

take manifold.

EXHAUST SYSTEM AND CATALYTIC CONVERTER INSPECTION AND MAINTENANCE

IMPORTANT: The exhaust system on this emission certi

ﬁed engine contains a Heated Exhaust Gas Oxygen Sensor (HEGO) which provides feed back to the ECM on the amount of oxygen present in the exhaust stream after combustion.

The measurement of oxygen in the exhaust stream is measured in voltage and sent to the ECM. The ECM then makes corrections to the fuel air ratio to ensure the proper fuel charge and optimum catalytic performance. Therefore, it is important that the exhaust connections remain secured and air tight.

IMPORTANT: The HEGO sensor is sensitive to silicone based products. Do not use silicone sprays or hoses which are assembled using silicone lubricants. Silicone contamination can cause severe damage to the HEGO.

When inspecting the Exhaust system check the following:

 Exhaust manifold at the cylinder head for

leaks and that all retaining bolts and shields (if used) are in place.

 Manifold to exhaust pipe fasteners to ensure

they are tight and that there are no exhaust leaks repair if necessary.

 HEGO electrical connector to ensure connec-

tor is seated and locked, check wires to ensure there is no cracking, splits chafing or “burn through.” Repair if necessary.

 Exhaust pipe extension connector for leaks

tighten if necessary

 Visually inspect converter to ensure muffler is

securely mounted and tail pipe is properly aimed.

 Check for any leaks at the inlet and outlet of

the converter.

LPG

& BI

FUEL

CERTIFIED ENGINE MAINTENANCE REQUIREMENTS

Perform the following maintenance on the engine at the hours indicated and at equivalent hour intervals thereafter.

Interval Hours

Daily 1000 1500 2000 2500 3000 3500 4000 4500 5000

General Maintenance Section

Visual check for fluid leaks

Check engine oil level

Check coolant level

Change engine oil and filter

Every 100 hours or 60 days of operation

Check LPG

system for leaks Prior to any service or maintenance activity

Inspect accessory drive belts for cracks, breaks, splits or glazing

X X X X X

Inspect

electrical system wiring for cuts, abrasions or corrosion X X

Inspect all vacuum lines and fittings for cracks, breaks or harden

ing X X

Engine Coolant Section

Clean debris from radiator core

Every 100 hours or 60 days of operation

Change coolant

X X X X X

Inspect coolant hoses for cracks, swelling or deterioration

X X X X X

Engine Ignition System

Inspect Battery case for leaks or damage

X X X X X

Inspect battery cables for damage corrosion or contamination

X X X X X

Check all electrical connector retainer locks

X X X X X

Replace spark plugs

X X

Fuel System Maintenance

Inspect air cleaner

Every 200 hours, or every 100 hours in dusty environment

Replace filter element

Annually, or Bi-annually in dusty environments

Replace PCV Valve

Replace inline LPG fuel filter

X X X X X

Check LPG shut off solenoid valve function

X X

Replace fuel filter

(Bi-fuel only) X X X X X

Inspect

Shut-off Valve for leaks and closing X X

Leak check

fuel lines X X

Check air induction for leaks

X X

Check manifold for

vacuum leaks X X Check fuel injector s& rail for leaks (Bi-fuel only) X X Replace fuel injectors (Bi-fuel only) X

Inspect

EPR for coolant leaks

Annually or every 2000 hours

Drain

EPR oil build up

Every 2500 hrs

Engine

Exhaust System

Inspect exhaust manifold for leaks

X X

Inspect exhaust piping for leaks

X X

Check HEGO sensor connector and wires for burns, cuts or damage

X X

Inspect catalyst for mechanical damage

X X

This maintenance schedule represents the manufacturer’s recommended maintenance intervals to maintain proper engine/equipment function. Federal, State, or Local regulations may require additional or more frequent inspection or maintenance intervals than those specified above. Check with the authority having jurisdiction for details. Note that LPG engines are designed to operate on HD–5 or HD–10 specification LPG fuel. Fuel other than HD–5 or HD–10 may cause harm to the engine’s emission control system and a warranty claim may be denied on this basis if operators can readily find the proper fuel*. Use of any other fuel may result in your engine no longer operating in compliance with CARB or EPA emissions requirements. *Not Applicable in the state of California.

LPG Fuel System

LPG FUEL SYSTEM OPERATION

DESCRIPTION AND OPERATION OF THE FUEL

SYSTEMS

LPG FUEL SYSTEM

The primary components of the LPG fuel system are the Fuel Storage Tank, Electronic Pressure Regulator (EPR), Fuel Mixer, Throttle Control Device, electric Shut-Off Valve, Engine Control Module (ECM), Oxygen Sensor and a Catalytic Converter. The system operates at pressures which range from 355.60mm (14.0 inches) of water column up to 21.5 BAR (312 psi).

LPG FUEL TANK

LPG is stored in the fuel tank as a liquid. The approximate pressure of the fuel in the tank is 8.8 bar (130 psi) when the tank is full at an ambient temperature of 27° C (81°F). The boiling point, (temperature at which the liquid fuel becomes vapor) is approximately 40° C (-40° F). When the fuel changes from liquid to vapor the fuel expands and creates pressure inside the tank. When the tank service valve is opened the pressure inside the tank forces the liquid fuel out though the pickup tube located near the bottom of the fuel cylinder.

Because the LPG is stored under pressure the tank is equipped with a safety valves which are normally set at 25.8 bar (375 psi) to prevent tank rupture due to over-pressurization of the cylinder. The service valve mounted in the end of the cylinder controls the

ﬂow of fuel from the tank. By turning the handle

to its “open” position, fuel ﬂows out of the tank and into the service line. The service valve is also equipped with a safety feature called an excess

ﬂow check valve. This feature reduces the ﬂow

from the service valve in the event of a rupture of the fuel line or any downstream.

Typical LPG Cylinder

1. Liquid Outage Fill Check Valve

2. Pressure Relief Valve

3. Liquid Outage Valve w/quick disconnect coupling (also referred to as the manual shut-off valve or MSV).

4. Filler Valve

5. Fuel Gauge

6. Vapor Withdrawal Tube (when applicable)

7. 80% Limiter Tube

8. Fuel Level Float

9. Liquid Withdrawal Tube

SERVICE LINE

LPG ﬂows from the fuel tank to the electric LPG Shut-Off Valve via the service line. The service line is connected to the tank utilizing a quick

coupler. The other end of the service line is connected to a bulkhead connector mounted on the equipment sheet metal. This bulkhead connector allows for a safe means of passing through the equipments engine compartment sheet metal and into the engine compartment. If a bulkhead connector is used a pressure relief device is mounted in the service line or the connector itself to prevent over pressurization. The service line is made of high pressure hose with special material or possibly tubing which is compatible with the LPG fuel and should always be replaced with an OEM supplied part.

The bulkhead assembly should never be removed. Never run a service line through the sheet metal.

FUEL FILTER

LPG, fuel like all other motor fuels is subject to contamination from outside sources. Refueling of the equipment tank and removal of the tank from the equipment can inadvertently introduce dirt and other foreign matter into the fuel system. It is therefore necessary to

ﬁlter the fuel prior to entering the fuel system components downstream of the tank. An inline fuel

ﬁlter has been installed in the fuel system to remove the dirt and foreign matter from the fuel, which is replaceable as a unit only. Maintenance of the

ﬁlter is critical to

proper operation of the fuel system and should be replaced according to the maintenance schedule or more frequently under severe operating conditions.

Inline Fuel Filter

LPG SHUT-OFF VALVE

The LPG Shut-Off Valve is an integrated assembly consisting of a 12 volt solenoid and a normally closed valve. When energized, the solenoid opens the valve and allows the LPG fuel to

ﬂow through

the device. The valve opens during cranking and engine run cycles.

LPG Shut-Off Valve

Voltage to the LPG Shut-Off Valve is controlled by the engine control module (ECM).

ELECTRONIC PRESSURE REGULATOR (EPR)

The EPR is a combination vaporizer and pressure regulating device. The EPR functions as a negative pressure two stage regulator that is normally closed with the ability to supply additional fuel by command from the ECM. When the engine is cranking or running, a partial vacuum is created in the fuel line which connects the regulator to the mixer. This partial vacuum opens the regulator permitting fuel to

ﬂow to the mixer.

LPG fuel enters the primary port of the EPR and passes through the primary jet and into the primary/heat exchanger chamber and expands as it heats up, creating pressure inside the chamber. When the pressure increases above 10.34 kPa

(3.5 psi), sufficient pressure is exerted on the

primary diaphragm to cause the diaphragm plate to pivot and press against the primary valve pin, thus closing off the

ﬂow of fuel. When the engine is cranking, sufficient vacuum will be introduced into the secondary chamber from the mixer drawing the secondary diaphragm down onto the spring loaded lever and opening the secondary valve. An increase in vacuum in the secondary chamber increases the downward action on the secondary lever, causing it to open wider and permitting more fuel

ﬂow to the mixer.

Electronic Pressure Regulator

The EPR is an emission control device and should only be serviced by qualified technicians.

AIR FUEL MIXER

The air valve mixer is a completely self-contained air-fuel metering device. The mixer is an air valve design, utilizing a relatively constant pressure drop to draw fuel into the mixer from cranking to full load. The mixer is mounted in the air stream ahead of the throttle control device.

When the engine begins to crank it draws in air with the air valve covering the inlet, and negative pressure begins to build. This negative pressure signal is communicated to the top of the air valve chamber through 4 vacuum ports in the air valve assembly. A pressure/force imbalance begins to build across the air valve diaphragm between the air valve vacuum chamber and the atmospheric pressure below the diaphragm. The air valve vacuum spring is calibrated to generate from 101.6 mm (4.0 inches) of water column at start to as high as 355.60 mm (14.0 inches) of water column at full throttle. The vacuum being created is referred to as Air Valve Vacuum (AVV). As the air valve vacuum reaches 101.6mm (4.0 inches) of water column, the air valve begins to lift against the air valve spring. The amount of AVV generated is a direct result of the throttle position. At low engine speed the air valve vacuum and the air valve position is low thus creating a small venturi for the fuel to

ﬂow. As the

engine speed increases the AVV increases and the air valve is lifted higher thus creating a much larger venturi. This air valve vacuum is communicated from the mixer venturi to the EPR secondary chamber via the low pressure fuel supply hose. As the AVV increases in the secondary chamber the secondary diaphragm is drawn further down forcing the secondary valve lever to open wider.

The mixer is equipped with a low speed mixture adjustment retained in a tamper proof housing. The mixer has been preset at the factory and should not require adjustment. In the event that the idle adjustment should need to be adjusted refer to the Fuel System Repair section of this manual.

The air/fuel mixer is an emission control device. Components inside the mixer are specifically calibrated to meet the engine’s emissions requirements and should never be disassembled or rebuilt. If the mixer fails to function correctly, replace with an OEM replacement part.

THROTTLE CONTROL DEVICE—DRIVE BY WIRE

Drive By Wire Engine speed control is maintained by the amount of pressure applied to the foot pedal located in the engine compartment. In a Drive By Wire (DBW) application, there is no direct connection between the operator pedal and the throttle shaft. Speed and load control are determined by the ECM. Defaults programmed into the ECM software and throttle position sensors allow the ECM to maintain safe operating control over the engine. In a drive by wire application the Electronic Throttle Control device or throttle body assembly is connected to the intake manifold of the engine. The electronic throttle control device utilizes an electric motor connected to the throttle shaft. In addition, a Foot Pedal Position sensor (FPP) is located in the operator’s compartment.

When the engine is running electrical signals are sent from the foot pedal position sensor to the engine ECM when the operator depresses or release the foot pedal. The ECM then sends an electrical signal to the motor on the electronic throttle control to increase or decrease the angle of the throttle blade thus increasing or decreasing the air/fuel charge to the engine. The electronic throttle control device incorporates two internal Throttle Position Sensors (TPS) which provide output signals to the ECM as to the location of the throttle shaft and blade. The TPS information is used by the ECM to correct for speed and load control as well as emission.

CATALYTIC CONVERTER

The Catalytic Converter is a component of the emissions system which is designed and calibrated to meet the emission standards in effect for 2007-2009 model year.

The exhaust gases pass through the honeycomb catalyst which is coated with a mixture of metals (such as platinum, palladium, and rhodium) to oxidize and reduce CO, HC and NOX emission gases.

Catalytic Converter/Muffler

ENGINE CONTROL MODULE

To obtain maximum effect from the catalyst and accurate control of the air fuel ratio, the emission certi

ﬁed engine is equipped with an onboard

computer or Engine Control Module (ECM). The ECM is a 32 bit controller which receives input data from sensors mounted to the engine and fuel system and then outputs various signals to control engine operation.

Engine Control Module (ECM)

One speciﬁc function of the controller is to maintain a closed loop fuel control which is accomplished by use of the Heated Exhaust Gas

Oxygen sensor (HEGO) mounted in the exhaust system. The HEGO sensor sends a voltage signal to the controller which then outputs signals to the EPR to change the amount of fuel being delivered from the regulator or mixer to the engine.

The controller also performs diagnostic functions on the fuel system and noti

ﬁes the operator of

engine malfunctions by turning on a Malfunction Indicator Light (MIL) mounted in the dash. Malfunctions in the system are identi

ﬁed by a

Diagnostic Trouble Code (DTC) number. In addition to notifying the operator of the malfunction in the system, the controller also stores the information about the malfunction in its memory. A technician can than utilize a computerized diagnostic scan tool to retrieve the stored diagnostic code and by using the diagnostic charts in this manual to determine the cause of the malfunction. In the event a technician does not have the computerized diagnostic tool, the MIL light can be used to identify the diagnostic code to activate the “blink” feature and count the number of blinks to determine the diagnostic code number to locate the fault in the system.

HEATED EXHAUST GAS OXYGEN SENSORS

The Heated Exhaust Gas Oxygen (HEGO) Sensors are mounted in the exhaust system, one upstream and one downstream of the catalytic converter. The HEGO sensors are used to measure the amount of oxygen present in the exhaust stream to determine whether the fuel air ratio is to rich or to lean. It then communicates this measurement to the ECM. If the HEGO sensor signal indicates that the exhaust stream is too rich, the ECM will decrease or lean the fuel mixture during engine operation. If the mixture is too lean, the ECM will richen the mixture. If the ECM determines that a rich or lean condition is present for an extended period of time which cannot be corrected, the ECM will set a diagnostic code and turn on the MIL light in the dash.

By monitoring output from the sensor upstream and the sensor downstream of the catalytic converter, the ECM can determine the performance of the converter.

The Heat Exhaust Gas Oxygen (HEGO) Sensor

HEGO1 (upstream or before the catalytic converter) and HEGO2 (downstream) voltage output.

The Heated Exhaust Gas Oxygen Sensor (HEGO) is an emissions control component. In the event of a failure, the HEGO should only be replaced with the recommended OEM replacement part. The HEGO is sensitive to silicone based products and can become contaminated. Avoid using silicone sealers or air or fuel hoses treated with a silicone based lubricant.

TMAP SENSOR

T–MAP Sensor

The Air Temperature/Manifold Absolute Pressure or TMAP sensor is a combination of two sensors:

1) A variable resistor used to monitor the differ-

ence in pressure between the intake manifold and outside or atmospheric pressure. The ECM monitors the resistance of the sensor to determine engine load (the vacuum drops when the engine is under load or at wide open throttle). When the engine is under load, the computer may alter the fuel mixture to improve performance and emissions.

2) The intake air temperature or IAT sensor is a

variable resistance thermistor located in the air intake passage which measures the temperature of the incoming air. The ECM uses the resistance value to monitor incoming air temperature and calculate the engine’s airflow requirement. The ECM provides a voltage divider circuit so that when the air is cool, the signal reads a higher voltage, and lower when warm. On cold starts, the ECM richens the fuel/air mixture.

COOLANT TEMPERATURE SENSOR

ECT

The Engine Coolant Temperature sensor or ECT is a variable resistance thermistor that changes resistance as the engine's coolant temperature

changes. The sensor's output is monitored by the ECM to determine a cold start condition and to regulate various fuel and emission control functions via a closed loop emission system.

OIL PRESSURE SENDER/SWITCH

The Oil Pressure Switch is Mounted on the side of the Engine Block

The Engine Oil Pressure switch or sender is designed to ensure adequate lubrication throughout the engine. It provides a pressure value for the oil pressure gauge and is monitored by the ECM. If the pressure drops, an MIL will occur.

LPG Closed Loop Schematic

LPG System Diagnosis

LPG FUEL SYSTEM DIAGNOSIS

The Electronic Pressure Regulator Assembly (EPR), Shown with Port Fittings and Shut-off Valve.

FUEL SYSTEM DESCRIPTION

The Engine Control Module (ECM) receives information from various engine sensors in order to control the operation of the Electronic Pressure Regulator (EPR) and Shut-Off Valve. The Shut-Off Valve solenoid prevents fuel

ﬂow un-

less the engine is cranking or running.

LPG is stored in the tank as a liquid and delivered under pressure of up to 21.5 BAR (312 psi). At Key ON, the EPR receives a two (2) second prime pulse from the ECM, allowing time for the LPG to

ﬂow from the tank through

the fuel

ﬁlter and fuel lines to the EPR. Inside of

the EPR, fuel is vaporized and reduced in pressure in two stages. The

ﬁrst stage reduces the

tank pressure to approximately 20.68 kilopascals (3.0 psi). The second stage then reduces the pressure to approximately negative 38.1 mm (1.5” of water column) when vacuum from the engine draws in fuel.

The fuel is then drawn in from the secondary chamber of the EPR by the vacuum generated by air

ﬂowing through the Mixer. This vacuum

is also generates lift for the mixer air valve and is commonly referred to as air valve vacuum. Once in the mixer, the fuel is combined with air and is drawn into the engine for combustion.

DIAGNOSTIC AIDS

This procedure is intended to diagnose a vehicle operating on LPG. If the vehicle will not continue to run on LPG, refer to Hard Start for preliminary checks. Before starting this proce-

dure, complete the following tasks to verify that liquid fuel is being delivered to the EPR:

 Inspect fuel tank to verify it has a sufficient

amount of fuel.

 Verify manual shut off valve on the LPG

tank is fully opened.

 Verify that the excess ﬂow valve has not

been activated.

 Inspect fuel tank to ensure it is properly

mounted and rotated to the correct position.

 Inspect the hoses leading from the tank en-

suring they are properly connected and do not have any kinks or damage.

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Impco HHI Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual