fuel ISUZU TROOPER 1998 Service User Guide

DRIVE LINE CONTROL SYSTEM (TOD) 4B2±92
Chart 3The shift on the fly system generates gear noises.
(The fuel economy is bad in the 2H mode.)
Function of circuitÐ
Fail conditionWhen the vehicle is run in the 2H mode, the shift on the fly system generates gear
noises or the front wheel gears are engaged to generate a shock.
D04RW055

TRANSFER CASE (STANDARD TYPE)
4D1±7
A/T, WO/Shift On The Fly, WO/4WD Switch, model
A07RW055
The transfer case is used to provide a means of providing
power flow to the front axle. The transfer case also
provides a means of disconnecting the front axle,
providing better fuel economy and quieter operation when
the vehicle is driven on improved roads where four wheel
drive is not required. In addition, the transfer case
provides an additional gear reduction when placed in low
range, which is useful when difficult off±road conditions
are encountered.
A floor mounted shift lever is used to select the high±low
range. When four wheel drive switch has been turned on,
the four wheel drive indicator light is designed to come on
when the front axle has been engaged.

4D2±3 TRANSFER CASE (TOD)
6. Disconnect the wiring harness connector and shift
lock cable and then remove the front console.
7. Remove the selector lever assembly and put it aside.
8. Remove the transfer control lever.
9. Disconnect the breather hose.
10. Remove the left front exhaust pipe fixing bolts and
nuts, and put the exhaust pipe aside.
11. Remove the left seat belt tension rod and put the rear
proper shaft aside.
260RW006
12. Remove the silencer.
13. Disconnect the transfer connector from the top of the
transfer case.
14. Disconnect the speed sensor harness connector.
15. Remove the fuel pipe clip fixing bolt on the transfer
case.
16. Support the transmission with a jack.
17. Remove the seven bolts from the transfer case.
18. Remove transfer case assembly.
Installation
To install, follow the removal steps in the reverse order,
nothing the following points:
1. Apply a thin coat of grease (Besco L2) or equivalent to
the input shaft spline.
261RW024
2. Mount the transfer case.

6A±1
ENGINE MECHANICAL
ENGINE
CONTENTS
Engine Mechanical 6A. . . . . . . . . . . . . . . . . . . . . .
Engine Cooling 6B. . . . . . . . . . . . . . . . . . . . . . . . .
Engine Fuel 6C. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Electrical 6D1. . . . . . . . . . . . . . . . . . . . . . . .
Ignition System 6D2. . . . . . . . . . . . . . . . . . . . . . . . .
Starting and Charging System 6D3. . . . . . . . . . . . Driveability and Emissions 6E. . . . . . . . . . . . . . . .
Engine Exhaust 6F. . . . . . . . . . . . . . . . . . . . . . . . .
Engine Lubrication 6G. . . . . . . . . . . . . . . . . . . . . .
Engine Speed Control System 6H. . . . . . . . . . . .
Inducton 6J. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ENGINE MECHANICAL
CONTENTS
Service Precaution 6A±2. . . . . . . . . . . . . . . . . . . . . .
General Description 6A±3. . . . . . . . . . . . . . . . . . . . .
Engine Diagnosis 6A±4. . . . . . . . . . . . . . . . . . . . . . .
Cylinder Head Cover LH 6A±18. . . . . . . . . . . . . . . . .
Removal 6A±18. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6A±19. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cylinder Head Cover RH 6A±21. . . . . . . . . . . . . . . . .
Removal 6A±21. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6A±22. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Common Chamber 6A±24. . . . . . . . . . . . . . . . . . . . . .
Removal 6A±24. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6A±24. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust Manifold LH 6A±26. . . . . . . . . . . . . . . . . . . . .
Removal 6A±26. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6A±26. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust Manifold RH 6A±27. . . . . . . . . . . . . . . . . . . .
Removal 6A±27. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6A±27. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankshaft Pulley 6A±28. . . . . . . . . . . . . . . . . . . . . . .
Removal 6A±28. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6A±28. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Timing Belt 6A±29. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 6A±29. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6A±30. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Camshaft 6A±33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 6A±33. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6A±33. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cylinder Head 6A±37. . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 6A±37. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6A±37. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve Stem Oil Controller , Valve Spring and
Valve Guide 6A±39. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 6A±39. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6A±39. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Piston, Piston Ring and Connecting Rod 6A±40. . . Removal 6A±40. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6A±41. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankshaft and Main Bearings 6A±42. . . . . . . . . . . .
Removal 6A±42. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6A±43. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear Oil Seal 6A±47. . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal 6A±47. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6A±47. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Assembly 6A±48. . . . . . . . . . . . . . . . . . . . . . . .
Removal 6A±48. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6A±48. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cylinder Head 6A±52. . . . . . . . . . . . . . . . . . . . . . . . . .
Cylinder Head and Associated Parts 6A±52. . . . .
Disassembly 6A±52. . . . . . . . . . . . . . . . . . . . . . . . . .
Clean 6A±53. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 6A±53. . . . . . . . . . . . . . . . . .
Reassembly 6A±53. . . . . . . . . . . . . . . . . . . . . . . . . .
Valve Spring, Oil Controller, Valve,
Valve Guide 6A±56. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve Spring, Oil Controller, Valve,
Valve Guide and Associated Parts 6A±56. . . . . . .
Disassembly 6A±56. . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 6A±57. . . . . . . . . . . . . . . . . .
Reassembly 6A±60. . . . . . . . . . . . . . . . . . . . . . . . . .
Valve Clearance Adjustments 6A±61. . . . . . . . . . . . .
Camshaft 6A±63. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Camshaft and Associated Parts 6A±63. . . . . . . . .
Disassembly 6A±63. . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 6A±64. . . . . . . . . . . . . . . . . .
Reassembly 6A±66. . . . . . . . . . . . . . . . . . . . . . . . . .
Crankshaft 6A±69. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankshaft and Associated Parts 6A±69. . . . . . . .
Disassembly 6A±69. . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and Repair 6A±70. . . . . . . . . . . . . . . . . .
Inspection and Repair 6A±71. . . . . . . . . . . . . . . . . .
Reassembly 6A±73. . . . . . . . . . . . . . . . . . . . . . . . . .

6A±3
ENGINE MECHANICAL
General Description
Engine Cleanliness And Care
An automobile engine is a combination of many
machined, honed, polished and lapped surfaces with
tolerances that are measured in the thousandths of a
millimeter (ten thousandths of an inch). Accordingly,
when any internal engine parts are serviced, care and
cleanliness are important. Throughout this section, it
should be understood that proper cleaning and protection
of machined surfaces and friction areas is part of the
repair procedure. This is considered standard shop
practice even if not specifically stated.

A liberal coating of engine oil should be applied to all
friction areas during assembly to protect and lubricate
the surfaces on initial operation.

Whenever valve train components, pistons, piston
rings, connecting rods, rod bearings, and crankshaft
journal bearings are removed for service, they should
be retained in order.

At the time of installation, they should be installed in
the same locations and with the same mating
surfaces as when removed.

Battery cables should be disconnected before any
major work is performed on the engine. Failure to
disconnect cables may result in damage to wire
harness or other electrical parts.

The six cylinders of this engine are identified by
numbers; Right side cylinders 1, 3 and 5, Left side
cylinders 2, 4 and 6, as counted from crankshaft
pulley side to flywheel side.
General Information on Engine Service
The following information on engine service should be
noted carefully, as it is important in preventing damage
and contributing to reliable engine performance:

When raising or supporting the engine for any reason,
do not use a jack under the oil pan. Due to the small
clearance between the oil pan and the oil pump
strainer, jacking against the oil pan may cause
damage to the oil pick±up unit.

The 12±volt electrical system is capable of damaging
circuits. When performing any work where electrical
terminals could possibly be grounded, the ground
cable of the battery should be disconnected at the
battery.

Any time the intake air duct or air cleaner is removed,
the intake opening should be covered. This will
protect against accidental entrance of foreign
material into the cylinder which could cause extensive
damage when the engine is started.
Cylinder Block
The cylinder block is made of aluminum die±cast casting
for 75
V±type six cylinders. It has a rear plate integrated
structure and employs a deep skint. The cylinder liner is
cast and the liner inner diameter and crankshaft journal
diameter are classified into grades. The crankshaft is
supported by four bearings of which width of No.3 bearing
on the body side is different in order to support the thrust
bearing. The bearing cap is made of nodular cast iron and
each bearing cap uses four bolts and two side bolts.
Cylinder Head
The cylinder head, made of aluminum alloy casting
employs a pent±roof type combustion chamber with a
spark plug in the center. The intake and exhaust valves
are placed in V±type design. The ports are cross±flow
type.
Valve Train
Intake and exhaust camshaft on the both side of banks
are driven through an camshaft drive gear by timing belt.
The valves are operated by the camshaft and the valve
clearance is adjusted to select suitable thickness shim.
Intake Manifold
The intake manifold system is composed of the aluminum
cast common chamber and intake manifold attached with
six fuel injectors.
Exhaust Manifold
The exhaust manifold is made of nodular cast iron.
Pistons and Connecting Rods
Aluminum pistons are used after selecting the grade that
meets the cylinder bore diameter. Each piston has two
compression rings and one oil ring. The piston pin is made
of chromium steel is offset 1mm toward the thrust side,
and the thrust pressure of piston to the cylinder wall varies
gradually as the piston travels. The connecting rods are
made of forged steel. The connecting rod bearings are
graded for correct seze selection.
Crankshaft and Bearings
The crankshaft is made of Ductile cast±iron. Pins and
journals are graded for correct size selection for their
bearing.
Engine Lubrication
The oil discharged by a trochoid±type oil pump driven by
the crankshaft is fed through full±flow oil filter and to the oil
gallery provided under the crankshaft bearing cap. The oil
is then led to the crankshaft journals and cylinder head.
The crank pins are lubricated with oil from crankshaft
journals through oil holes. Also, an oil jet is fed to each
cylinder from crankshaft juornals on the connecting rod
for piston cleaning. The oil pan flange is dealed with liquid
packing only; do not deform or damage the flange surface
during removal or installation.

6A±4
ENGINE MECHANICAL
Engine Diagnosis
Hard Starting
1. Starting Motor Does Not Turn Over
Troubleshooting Procedure
Turn on headlights and starter switch.
Condition
Possible causeCorrection
Headlights go out or dim
considerably
Battery run down or under chargedRecharge or replace battery
considerablyTerminals poorly connectedClean battery posts and terminals
and connect properly
Starting motor coil circuit shortedOverhaul or replace
Starting motor defectiveOverhaul or replace
2. Ignition Trouble Ð Starting Motor Turns Over But Engine Does Not Start
Spark Test
Disconnect an igniton coil from any spark plug. Connect
the spark plug tester 5±8840±0607±0, start the engine,
and check if a spark is generated in the spark plug tester.
Before starting the engine, make sure that the spark plugtester is properly grounded. To avoid electrical shock, do
not touch the part where insulation of the igniton coil is
broken while the engine is running.
Condition
Possible causeCorrection
Spark jumps across gapSpark plug defectiveClean, adjust spark gap or replace
Ignition timing incorrectRefer to Ignition System
Fuel not reaching fuel injector(s) or
engineRefer to item 3 (Trouble in fuel
system)
Valve timing incorrectAdjust
Engine lacks compressionRefer to item 4 (Engine lacks
compression)
No sparking takes placeIgnition coil disconnected or brokenConnect properly or replace
Electronic Ignition System with
moduleReplace
Poor connections in engine harnessCorrect
Powertrain Control Module cable
disconnected or defectiveCorrect or replace
3. Trouble In Fuel System
Condition
Possible causeCorrection
Starting motor turns over and spark
occurs but engine does not start
Fuel tank emptyFill
occurs but engine does not start.Water in fuel systemClean
Fuel filter cloggedReplace filter
Fuel pipe cloggedClean or replace
Fuel pump defectiveReplace
Fuel pump circuit openCorrect or replace
Evaporative Emission Control
System circuit cloggedCorrect or replace
Multiport Fuel Injection System faultyRefer to ªElectronic Fuel Injectionº
section

6A±5
ENGINE MECHANICAL
4. Engine Lacks Compression
Condition
Possible causeCorrection
Engine lacks compressionSpark plug loosely fitted or spark
plug gasket defectiveTighten to specified torque or replace
gasket
Valve timing incorrectAdjust
Cylinder head gasket defectiveReplace gasket
Valve incorrectly seatedLap valve
Valve stem seizedReplace valve and valve guide
Valve spring weakened or brokenReplace
Cylinder or piston rings wornOverhaul engine
Piston ring seizedOverhaul engine.
Engine Compression Test Procedure
1. Start and run the engine until the engine reaches
normal operating temperature.
2. Turn the engine off.
3. Remove all the spark plugs.
4. Remove ignition coil fuse (15A) and disable the
ignition system.
5. Remove the fuel pump relay from the relay and fuse
box.
6. Engage the starter and check that the cranking speed
is approximately 300 rpm.7. Install cylinder compression gauge into spark plug
hole.
8. With the throttle valve opened fully, keep the starter
engaged until the compression gage needle reaches
the maximum level. Note the reading.
9. Repeat the test with each cylinder.
If the compression pressure obtained falls below the
limit, engine overhaul is necessary.
Limit; 1000 kPa (145 psi)

6A±6
ENGINE MECHANICAL
Rough Engine Idling or Engine Stalling
ConditionPossible causeCorrection
Trouble in fuel injection systemIdle air control valve defectiveReplace
Throttle shutting off incompleteCorrect or replace
Throttle position sensor circuit open
or shortedCorrect or replace
Fuel injector circuits open or shortedCorrect or replace
Fuel injectors damagedReplace
Fuel pump relay defectiveReplace
Mass Airflow Sensor circuit open or
poor connectionsCorrect or replace
Mass Airflow Sensor defectiveReplace
Manifold Absolute Pressure Sensor
circuit open or poor connectionsCorrect or replace
Manifold Absolute Pressure Sensor
defectiveReplace
Engine Coolant Temperature Sensor
circuit open or poor connectionsCorrect or replace
Engine Coolant Temperature Sensor
defectiveReplace
Intake Air Temperature sensor circuit
open or poor connectionsCorrect or replace
Intake Air Temperature sensor
defectiveReplace
Knock Sensor (KS) cable broken or
poor connectionsCorrect or replace
KS defectiveReplace
KS Module circuits open or groundCorrect or replace
KS Module defectiveReplace
Vehicle Speed Sensor circuit open or
shortedCorrect or replace
Vehicle Speed Sensor defectiveReplace
Trouble in emission control systemPowertrain Control Module defectiveReplace
Exhaust Gas Recirculation Valve
circuit open or poor connectionsCorrect or replace
Exhaust Gas Recirculation Valve
faultyReplace
Canister purge valve circuit open or
poor connectionsCorrect or replace
Canister purge valve defectiveReplace
Evaporative Emission Canister
Purge control valve defectiveReplace
Trouble in ignition systemRefer to ªHard Startº

6A±7
ENGINE MECHANICAL
Condition CorrectionPossible cause
OthersEngine lacks compressionRefer to ªHard Startº
Valve incorrectly seatedLap valve
Air Cleaner Filter cloggedReplace filter element
Valve timing incorrectReadjust
Idle air control valve brokenReplace
Fast idle solenoid defectiveReplace
Positive Crankcase Ventilation valve
defective or cloggedReplace
Rough Engine Running
ConditionPossible causeCorrection
Engine misfires periodicallyIgnition coil layer shortedReplace
Spark plugs foulingClean or install hotter type plug
Spark plug(s) insulator nose leakingReplace
Fuel injector(s) defectiveReplace
Powertrain control module faultyReplace
Engine knocks periodicallySpark plugs running too hotInstall colder type spark plugs
Powertrain control module faultyReplace
Engine lacks powerSpark plugs fouledClean
Fuel injectors defectiveReplace
Mass Airflow Sensor or Intake
Airflow Sensor circuit defectiveCorrect or replace
Manifold Absolute Pressure (MAP)
Sensor or Manifold Absolute
Pressure Sensor circuit defectiveCorrect or replace
Engine Coolant Temperature Sensor
or Engine Coolant Temperature
Sensor circuit defectiveCorrect or replace
Powertrain Control Module faultyReplace
Intake Air Temperature Sensor or
Intake Air Temperature Sensor
circuit defectiveCorrect or replace
Throttle Position Sensor or Throttle
Position Sensor circuit defectiveCorrect or replace
Knock Sensor or Knock Sensor
circuits defectiveCorrect or replace
Knock Sensor Module or Knock
Sensor Module circuits defectiveCorrect or replace

6A±8
ENGINE MECHANICAL
Hesitation
ConditionPossible causeCorrection
Hesitation on accelerationThrottle Position Sensor adjustment
incorrectReplace throttle valve assembly
Throttle Position Sensor circuit open
or shortedCorrect or replace
Excessive play in accelerator linkageAdjust or replace
Mass Airflow Sensor circuit open or
poor connectionsCorrect or replace
Mass Airflow Sensor defectiveReplace
Manifold Absolute Pressure (MAP)
Sensor circuit open or shortedCorrect or replace
MAP Sensor defectiveReplace
Intake Air Temperature (IAT) Sensor
circuit open or shortedCorrect or replace
Knock Sensor (KS) Circuit open or
poor connectionsCorrect or replace
KS defectiveReplace
KS Module circuits open or shortedCorrect or replace
KS Module defectiveReplace
IAT Sensor defectiveReplace
Hesitation at high speedsFuel tank strainer cloggedClean or replace
(Fuel pressure too low)Fuel pipe cloggedClean or replace
Fuel filter cloggedReplace
Defective fuel pump systemCheck and replace
Fuel Pressure Control Valve leakingReplace
Hesitation at high speeds
(Fuel injector not working normally)Power supply or ground circuit for
Multiport Fuel Injection System
shorted or openCheck and correct or replace
Fuel Injector defectiveReplace
Cable of Multiport Fuel Injection
System circuit open or poor
connectionsCorrect or replace