check engine ISUZU TROOPER 1998 Service Repair Manual

6G±4
ENGINE LUBRICATION
11. Remove drive gear.
12. Remove oil seal.
13. Remove O-ring.
Inspection and Repair
CAUTION: M a k e necessary correction or parts
replacement if wear, damage or any other abnormal
conditions are found during inspection.
Relief Valve (8)

Check to see that the relief valve slides freely.

The oil pump must be replaced if the relief valve does
not slide freely.

Replace the spring and/or the oil pump assembly (5) if
the spring is damaged or badly worn.
051RS002
Body (14) and Gears (10, 11)
The pump assembly must be replaced if one or more of
the conditions below is discovered during inspection.

Badly worn or damaged driven gear (10).

Badly worn drive gear (11) driving face.

Badly scratched or scored body sliding face (14) or
driven gear (10).

Badly worn or damaged gear teeth.
Measure the clearance between the body and the driven
gear with a feeler gauge.
Standard : 0.10 mm±0.18 mm
(0.0039 in.±0.0070 in)
Limit : 0.20mm (0.0079 in)
051RS004

Measure the clearance between the drive gear and
driven gear with a feeler gauge.
Standard : 0.11 mm±0.24 mm
(0.0043 in±0.0094 in)
Limit : 0.35mm (0.0138 in)
051RS003

Measure the side clearance with a precision straight
edge and a feeler gauge.
Clearance
Standard : 0.03 mm±0.09 mm
(0.0011 in±0.0035 in)
Limit : 0.15mm (0.0059 in)

6G±5 ENGINE LUBRICATION
051RS005
Oil Strainer
Check the oil strainer for cracking and scoring. If cracking
and scoring are found, the oil strainer must be replaced.
051RS006
Reassembly
1. Install drive gear (11).
2. Install driven gear (10).
3. Install oil pump cover (9) and first, loosely tighten all of
the attaching screws. Next, tighten the attaching
screws to the specified torque.
Torque : 10 N´m (1.0 Kg´m/89 lb in)
After installation, check that the gear rotates
smoothly.
4. Install relief valve (8) and apply engine oil to the relief
valve and spring (7).
5. Install spring (7).6. Install the plug (6).
Torque : 8 N´m (0.8 Kg´m/69 lb in)
051RS007
7. Install oil pump assembly (5).

Carefully remove any oil from the cylinder body and
the pump. Apply sealant (TB±1207B or equivalent)
to the pump fitting face as shown in illustration. Take
care that sealant is not applied to oil port surfaces.
The oil pump assembly must be installed within 5
minutes after sealant application before the sealant
hardens.
CAUTION: Do not apply an excessive amount of
sealant to the contact surface. Applying too much
sealant will overflow the contact surfaces. This
could cause serious damage to the engine.

Attach oil pump assembly to cylinder body.

Tighten the oil pump fixing bolts.
Torque : 25 N´m (2.5 Kg´m/18 lb´ft)
051RW002

6H±2
ENGINE SPEED CONTROL SYSTEM
Accelerator Pedal Control Cable
Removal
1. Loosen the adjusting nut(5) on the cable bracket
mounted on the common chamber.
2. Remove cable clip(3).
3. Disconnect accelerator pedal (AP) control cable(6).
(on throttle valve side)
4. Disconnect AP control cable(1). (on AP pedal(7) side)
5. Remove molding cap(2).
6. Remove AP control cable(4).
101RW001
Inspection
Check the following items, and replace the control cable if
any abnormality is found:

The control cable should move smoothly.

The control cable should not be bent or kinked.

The control cable should be free of damage and
corrosion.
Installation
1. Install AP control cable(4).
2. Install molding cap(2).
3. Connect AP control cable(1). (on AP side)
4. Connect AP control cable(6). (on throttle valve side)
5. Install cable clip(3).
6. Install adjusting nut(5).
101RW001
Adjustment
1. Loosen adjusting nut and lock nut.
2. Pull outer cable while closing fully the throttle valve.
3. Tighten adjusting nut and lock nut temporarily.
4. Loosen adjusting nut by three turns and tighten lock
nut.
Then, manually operating the throttle valve, make
sure that the valve lever returns up to the stopper
screw.
If it does not reach the stopper screw, repeat from
step 1.
035RW004
Legend
(1) Clearance
(2) Lock Nut
(3) Adjusting Nut

SERVICE INFORMATION 00 Ð 3
1. HARD STARTING
Checkpoint Possible cause Correction
Battery Loose battery cable terminal
Poor connections due to rustingClean and/or retighten the battery
cable terminal
1. STARTER MOTOR INOPERATIVE
Battery discharged or weak Recharge or replace the battery
Fan belt loose or broken Adjust or replace the fan belt
Fusible link Fusible link shorted Replace the fusible link
Starter switch Defective starter switch or starter relay Replace the starter switch or the
starter relay
Starter motor Defective magnetic switch or starter relay Repair or replace the magnetic
switch
Defective starter motor Repair or replace the starter motor
2. STARTER MOTOR OPERATES BUT ENGINE DOES NOT TURN OVER
Battery Loose battery cable terminal
Poor connections due to rustingClean and/or retighten the battery
cable terminal
Battery discharged or weak Recharge or replace the battery
Fan belt loose or broken Adjust or replace the fan belt
Starter motor Defective pinion gear Replace the pinion gear
Defective magnetic switch Repair or replace the magnetic
switch
Brush wear, Weak brush spring Replace the brush and/or the brush
spring
Engine Piston, crank bearing seizuer, or other
damageRepair or replace the related parrts

00 Ð 4 SERVICE INFORMATION
Checkpoint Possible cause Correction
Engine stop
mechanismDefective fuel cut solenoid valve Replace the fuel cut solenoid valve
3. ENGINE TURNS OVER BUT DOES NOT START
FUEL IS NOT BEING DELIVERED TO THE INJECTION PUMP
Fuel Fuel tank is empty Fill the fuel tank
Fuel piping Clogged or damaged fuel lines. Loose fuel
line connectionRepair or replace the fuel lines
Retighten the fuel line connection
Fuel filter Fuel filter overflow valve does not close Repair or replace the fuel filter
overflow valve
Clogged fuel filter element Replace the fuel filter element or
the filter cartridge
Fuel system Air in the fuel system Bleed the air from the fuel system
Fuel feed pump Defective feed pump Repair or replace the feed pump
FUEL IS BEING DELIVERED TO THE INJECTION PUMP
Fuel Use of the wrong fuel Use the correct fuel
Water particles in the fuel Carge the fuel
Fuel system Air in the injection pump Bleed the air from the fuel system
Injection nozzle Injection nozzle sticking Replace the injection nozzle
Injection nozzle injection starting pressure
too low
Improper spray conditionAdjust or replace the injection
nozzle
Injection pump Defective fuel injection nozzle resulting in
the fuel drippage after fuel injectionReplace the delivery valve
Defective injection pump control rack
operationRepair or replace the injection pump
control rack
Injection pump plunger worn or stuck Replace the injection pump plunger
assembley
Injection pump drive shaft seizure or other
damageReplace the injection drive shaft
Injection pump governor spring seizure Replace the injection pump
governor spring

SERVICE INFORMATION 00 Ð 9
4. EXCESSIVE FUEL CONSUMPTION
5. EXCESSIVE OIL CONSUMPTION
Checkpoint Possible cause Correction
Engine oil Engine oil unsuitable
Too mauch engine oilReplace the engine oil
Correct the engine oil level
Oil seal and gasket Oil leakage from the oilseal and/or the
gasketReplace the oil seal and/or the
gasket
Air breather Clogged air breather Clean the air breather
Intake and exhaust
valveWorn valve stems and valve guides Replace the intake and exhaust
valves and the valve springs
Checkpoint Possible cause Correction
Fuel system Fuel leakage Repair or replace the fuel system
related parts
Air cleaner Clogged air cleaner element Clean or replace the air cleaner
element
Idling speed Poorly adjusted idling speed Adjust the idling speed
Injection nozzle Injection nozzle injection starting pressure
too low
Improper spray condition Adjust or replace the injection
nozzle
Fuel injection timing Fuel injection timing improperly Adjust the fuel injection timing
Injection pump Defective Delivery valve resulting is fuel
drippage after fuel injectionReplace the delivery valve
Turbocharger Air leakage from the turbocharger intake
sideRepair the turbocharger intake side
Defective turbocharger assembly Replace the turbocharger assembly
Valve clearance Valve clearance improperly adjusted Adjust the valve clearance
Compression
pressureBlown out cylinder head gasket. Worn
cylinder liner.
Piston ring sticking between the valve and
valve seatReplace the related parts
Valve spring Valve spring weak or broken Replace the valve spring

SERVICE INFORMATION 00 Ð 11
8. DARK EXHAUST SMOKE
Checkpoint Possible cause Correction
Air cleaner Clogged air cleaner element Clean or replace the air cleaner
element
Injection nozzle Injection nozzle injection starting pressure
too low
Improper spray conditionAdjust or replace the injection
nozzle
Fuel injection timing Fuel injection timing improperly adjusted Adjust the fuel injection timing
Injection pump Defective Delivery valve resulting is fuel
drippage after fuel injectionReplace the delivery valve
Excessive injection volume Adjust the injection volume
9. OIL PRESSURE DOES NOT RISE
Checkpoint Possible cause Correction
Engine oil Improper viscosity engine oil. Insufficient
engine oilReplace the engine oil
Correct the engine oil volume
Oil pressure gauge
or unit
Oil pressure indicator
lightDefective oil pressure gauge or unit
Defective indicator lightRepair or replace the oil pressure
gauge or unit
Replace the indicator light
Oil filter Clogged oil filter element Replace the oil filter element or the
oil filter cartridge
Relief valve and by-
pass valveRelief valve sticking and/or weak by-pass
valve springReplace the relief valve and/or the
by-pass valve spring
Oil pump Clogged oil pump strainer Clean the oil pump strainer
Worn oil pump related parts Replace the oil pump related parts
Rocker arm shaft Worn rocker arm bushing Replace the rocker arm bushing
Camshaft Worn camshaft and camshaft bearing Replace the camshaft and the
camshaft bearing
Crankshaft and
bearingsWorn crankshaft and bearings Replace the crankshaft and/or the
bearings

00 Ð 12 SERVICE INFORMATION
10. ABNORMAL ENGINE NOISE
Checkpoint Possible cause Correction
Fuel Fuel unsuitable Replace the fuel
1. ENGINE KNOCKING
2. GAS LEAKAGE NOISE
Exhaust pipes Loosely connected exhaust pipes. Broken
exhaust pipesTighten the exhaust pipe
connections
Replace the exhaust pipes Check to see that the engine has been thoroughly warmed up before begining the troubleshooting
procedure.
Fuel injection timing Fuel injection timing improperly adjusted Adjust the fuel injection timing
Injection nozzle Improper injection nozzle starting pressure
and spray conditionAdjust or replace the injection
nozzle
Compression
pressureBlown out head gasket
Broken piston ringReplace the head gasket or the
piston ring
Injection nozzles
and/or glow plugsLoose injection nozzles and/or glow plugs Replace the washers
Tighten the injection nozzles and/or
the glow plugs
Exhaust manifold Loosely connected exhaust manifold and/or
glow plugsTighten the exhaust manifold
connections
Cylinder head gasket Damaged cylinder head gasket Replace the cylinder head gasket
3. CONTINUOUS NOISE
Fan belt Loose fan belt Readjust the fan belt tension
Cooling fan Loose coling fan Retighten the cooling fan
Water pump bearing Worn or damaged water pump bearing Replace the water pump bearing
Alternator or vacuum
pumpDefective alternator or vacuum pump Repair or replace the alternator or
the vacuum pump
Valve clearance Clearance improperly adjust Adjust the valve clearance

SERVICE INFORMATION 00 Ð 15
ENGINE ELECTRICAL
Check if the battery is normal, then perform the following diagnosis.
STARTER DOES NOT RUN
CHECK BATTERY
CHARGING FAILURE OR LIFE
CHECK BATTERY
BATTERY IS NORMAL
CHECK TERMINAL CONNECTION
CONNECTION FAILURE
CLEAN BATTERY TERMINALS, AND RECONNECT
TERMINAL CONNECTION IS NORMAL
CHECK STARTER OR STARTER SWITCH
FAILURE
REPAIR OR REPLACE
TURN ON HEAD LAMP AND STARTER SWITCH
HEAD LAMP DOES NOT COME ON
OR IT IS EXTREMELY DARK
a) LACK OF BATTERY CHARGING
b) SHORT-CIRCUIT IN STARTER COIL
c) FAULTY STARTER PARTS
HEAD LAMP ILLUMINATES
a) DISCONNECTED STARTER CIRCUIT
b) DISCONNECTED STARTER COIL
c) FAULTY STARTER SWITCH

00 Ð 18 SERVICE INFORMATION
PINION MESHES WITH RING GEAR BUT
ENGINE DOES NOT RUN
CHECK GROUND CABLE
YESNO
REPAIR OR REPLACE
GROUND CABLE
FAULTY CONNECTION
OF BRUSH AND
COMMUTATORBURNED-OUT
MAGNETIC
STARTER SWITCHDISCONNECTION
OR DAMAGE OF
FIELD COILDISCONNECTION
OR DAMAGE OF
ARMATURE COILSLIP OF
PINION
CLUTCH
REPAIR OR REPLACE STARTER