1998 ISUZU TROOPER fuel filter

00 Ð 6 SERVICE INFORMATION
Checkpoint Possible cause Correction
Injection timing improperly adjusted Adjust the injection timing
Insufficient injection volume Adjust the injection volume
Defective idle spring Replace the idle spring
Defective governor lever operation Repair or replace the governor
lever
Regulator valve improperly adjustment Adjust or replace the regulator valve
Broken plunger spring Replace the plunger spring
Worn plunger Replace the plunger assembly
Worn cam disc Replace the cam disc
Valve clearance improperly adjusted Adjust the valve clearance Valve clearance
Blown out cylinder head gasket. Worn
cylinder liner.
Piston ring sticking between
the valve and the valve seatReplace the related parts Compression
pressure
Fuel system leakage or blockage Repair or replace the fuel system Fuel system
Air in the fuel system Bleed the air from the fuel system
Water particles in the fuel system Change the fuel
Clogged fuel filter element Replace the fuel filter element or
the fuel filter cartridge Fuel filter
Defective fuel feed pump Repair or replace the fuel feed pump Fuel feed pump
Injection nozzle sticking Replace the injection nozzle Injection nozzle
Injection nozzle injection starting pressure
too low
Improper spray conditionAdjust or replace the injection
nozzle
Defective delivery valve resulting in fuel
drippage after fuel injectionReplace the delivery valve Injection pump

SERVICE INFORMATION 00 Ð 7
3. INSUFFICIENT POWER
Clogged air cleaner element Clean or replace the air cleaner
element Air cleaner
Checkpoint Possible cause Correction
Water particle in the fuel Replace fuel Fuel
Clogged fuel filter element Replace the fuel filter element or
the fuel filter cartridge Fuel filter
Defective fuel feed pump Repair or replace the fuel feed pump Fuel feed pump
Injection nozzle sticking Replace the injection nozzle Injection nozzle
Injection nozzle injection starting pressure
too low
Improper spray conditionAdjust or replace the injectionn
nozzle
Fuel injection pipes damaged or obstructed Replace the fuel injection pipes Fuel injection pipes
Defective regulating valve Repair or replace the regulating
valve Injection pump
Defective delivery valve Replace the delivery valve
Defective timer Repair or replace the timer
Worn cam disk Replace the cam disk
Improper control lever operation Adjust or replace the control lever
Defective injection timing Adjust the injection timing
Repair or replace the injection pump
timer
Weak governor spring Replace the governor spring
Worn plunger Replace the plunger saaembly
Worn cam disk Replace the cam disk

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

SERVICE INFORMATION 00 Ð 29
FUEL SYSTEM
Fuel Filter
Replacement Procedure
1. Loosen the used fuel filter by turning it counterclock-
wise with the filter wrench.
Filter Wrench: 5-8840-0253-0 (J-22700)
2. Remove the level sensor from the filter by turning it
counterclockwise with a wrench.
3. Install the level sensor to the new fuel filter with a
wrench.
5. Apply a light coat of engine oil to the O-ring.
6. Turn in the fuel filter until the sealing face comes in
contact with the O-ring.
7. Turn in the fuel filter an additional 2/3 of a turn with a
filter wrench.
Filter Wrench: 5-8840-0253-0 (J-22700)
8. Loosen the bleeder plug on the injection pump overflow
valve.
9. Operate the priming pump until fuel begins to flow from
the fuel filter.
10. Retighten the bleeder plug.
11. Operate the priming pump several times and check for
fuel leakage.
NOTE:
The use of an ISUZU genuine fuel filter is strongly recom-
mended.
13 (1.3/9)
N·m (Kg·m/lb·ft) Level Sensor Torque
4. Clean the filter cover fitting faces.
This will allow the new fuel filter to seat properly.

00 Ð 30 SERVICE INFORMATION
Fuel Filter Water Draining Procedure
The indicator light will come on when the water level in the
water separator exceeds the specified level.
Drain the water and foreign material from the water separa-
tor with the following procedure.
1. Find a safe place to park the vehicle.
2. Open the engine hood and place a container (Approxi-
mately 0.2 liter capacity) at the end of the vinyl hose
beneath the drain plug on the separator.
3. Loosen the drain plug by turning it counterclockwise
(Approximately 5 turns) and operate the priming pump
up and down about 10 times until water is drained
approximately 0.1 liter.
4. After draining, securely tighten the drain plug by turn-
ing it clockwise and operate the priming pump manu-
ally up and down several times.
5. After starting the engine, check to see that there is no
fuel leak from the drain plug.
Also check to see that the fuel filter water indicator light
has turned off.
If water separator requires frequent draining, have the
fuel tank drained for removal of water at your Isuzu
Dealer.
Air Bleeding
1. Loosen the bleeder screw on the injection pump over-
flow valve.
2. Operate the priming pump until fuel mixed with foam
flows from the bleeder screw.
3. Tighten the bleeder screw.
4. Operate the priming pump several times and check for
fuel leakage.
COOLING SYSTEM
Coolant Level
Check the coolant level and replenish the radiator reserve
tank as necessary.
If the coolant level falls below the ÒMINÓ line, carefully check
the cooling system for leakage. Then add enough coolant to
bring the level up to the ÒMAXÓ line.
NOTE:
Do not overfill the reserve tank.

00 Ð 48 SERVICE INFORMATION
SPECIAL TOOLS (CONT.1)
5-8840-0145-0
5-8522-0024-0
5-8840-0266-0
5-8840-9016-0
5-8840-2038-0
5-8840-2061-0
ILLUSTRATION
TOOL NAME TOOL NO.
Measuring Device
Crankshaft Timing Gear Installer
Angle Gauge
Injection Nozzle Tester
Bearing Replacer
Crankshaft Front Oil Seal Installer
5-8840-2032-0
5-8840-0259-0
5-8840-0253-0 (J-22700)Engine Hanger
Nozzle Holder Wrench
Fuel Filter Wrench
5-8840-2360-0 Crankshaft Rear Oil Seal Remover
5-8840-2359-0 Crankshaft Rear Oil Seal Installer

FUEL SYSTEM 6C Ð 1
PAGE
General Description ....................................................................................................................... 6C- 1
On-Vehicle Service ......................................................................................................................... 6C- 7
Fuel Filter Assembly .................................................................................................................. 6C- 7
Fuel Filter Cartrige ..................................................................................................................... 6C- 8
Injection nozzle .......................................................................................................................... 6C- 9
Injection Pump Assembly ......................................................................................................... 6C-14
Fuel Tank .................................................................................................................................... 6C-18
Fuel Gauge Unit ......................................................................................................................... 6C-19
Fuel Filler Cap ............................................................................................................................ 6C-20
Accelerator Control ........................................................................................................................ 6C-21
Accelerator Control Cable ........................................................................................................ 6C-21
Accelerator Pedal ...................................................................................................................... 6C-23
Air Cleaner .................................................................................................................................. 6C-24
SECTION 6C
FUEL SYSTEM
CONTENTS
GENERAL DESCRIPTION
When working on the fuel system, there are several
things to keep in mind:
·Any time the fuel system is being worked on,
disconnect the negative battery cable except for
those tests where battery voltage is required.
·Always keep a dry chemical (Class B) fire extin-
guisher near the work area.
·Replace all pipes with the same pipe and fittings
that were removed.
Clean and inspect ÒOÓ rings. Replace where
required.
·Always relieve the line pressure before servicing
any fuel system components.·Do not attempt repairs on the fuel system until
you have read the instructions and checked the
pictures relating to that repair.

6C Ð 2 FUEL SYSTEM
General Export
Argentina
INJ. pump
Fuel filterWater separatorFuel feed pipe Fuel return pipe
Fuel tankFiller cap
Control valve
INJ. pump
Fuel filterWater separator
Air cleaner
Breather pipeFuel feed pipe Fuel return pipe
Fuel tank
Roll over & float valve Filler cap
Control valve
140RX024
140RX025