fuel cap ISUZU TROOPER 1998 Service Repair Manual

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±24
ENGINE MECHANICAL
Common Chamber
Removal
1. Disconnect battery ground cable.
2. Remove air cleaner duct assembly.
130RW001
Legend
(1) Positive Crankcase Ventilation Hose Connector
(2) Intake Air Temperature Sensor
(3) Air Cleaner Duct Assembly
(4) Air Cleaner Element
(5) Air Flow Sensor
3. Disconnect accelerator pedal cable from throttle body
and cable bracket.
4. Disconnect vacuum booster hose from common
chamber.
5. Disconnect connector from manifold absolute
pressure sensor, idle air control valve, throttle
position sensor, solenoid valve, electric vacuum
sensing valve, and EGR valve.
6. Disconnect vacuum hose on canister VSV and
positive crankcase ventilation hose, fuel rail
assembly with pressure control valve bracket.
7. Remove ventilation hose from throttle valve and
intake duct and remove water hose.
8. Remove the four throttle body fixing bolts.
9. Remove exhaust gas recirculation valve assembly
fixing bolt and nut on common chamber and remove
EGR valve assembly.
10. Remove two bolts from common chamber rear side
for remove fuel hose bracket.
11. Remove common chamber four bolts and four nuts
then remove the common chamber.
025RW001
Legend
(1) Common Chamber
(2) Throttle Valve Assembly
(3) Bolt
Installation
1. Install common chamber and tighten bolts and nuts to
the specified torque.
Torque :
Bolt : 25 N´m (2.5 Kg´m/18 lb ft)
Nut : 25 N´m (2.5 Kg´m/18 lb ft)
2. Install fuel hose bracket and tighten bolts to specified
torque.
Torque : 10 N´m (1.0 Kg´m/89 lb in)
3. Install exhaust gas recirculation valve assembly and
tighten bolt and nut to the specified torque.
Torque : 25 N´m (2.5 Kg´m/18 lb ft)
4. Install throttle body and tighten bolts to the specified
torque.
Torque : 25 N´m (2.5 Kg´m/18 lb ft)
5. Install ventilating hose to throttle valve and intake
duct.
6. Connect vacuum hoses on canister VSV and positive
crankcase ventilation hose. Tighten bolts for fuel rail
assembly with pressure control valve bracket.
Torque : 25 N´m (2.5 Kg´m/18 lb ft)
7. Connect each connector without fail.
8. Connect vacuum booster hose.
9. Connect accelerator pedal cable.
Accelerator pedal cable adjustment
1. Loosen the adjusting nut and screw cap.
2. Pull outer cable while fully closing the throttle
valve.

6C±1
ENGINE FUEL
ENGINE
ENGINE FUEL
CONTENTS
Service Precaution 6C±1. . . . . . . . . . . . . . . . . . . . . .
General Description 6C±2. . . . . . . . . . . . . . . . . . . . .
Fuel Metering 6C±3. . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Filter 6C±4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Filter and Associated Parts 6C±4. . . . . . . . .
Removal 6C±4. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection 6C±4. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6C±5. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection 6C±5. . . . . . . . . . . . . . . . . . . . . . . . . . . .
In±Tank Fuel Filter 6C±5. . . . . . . . . . . . . . . . . . . . .
Fuel Pump Flow Test 6C±5. . . . . . . . . . . . . . . . . . .
Fuel Pump 6C±6. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Pump and Associated Parts 6C±6. . . . . . . .
Removal 6C±6. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6C±6. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Pump Relay 6C±7. . . . . . . . . . . . . . . . . . . . . . . .
General Description 6C±7. . . . . . . . . . . . . . . . . . . . .
Fuel Tank 6C±7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fuel Tank and Associated Parts 6C±7. . . . . . . . .
Removal 6C±7. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6C±8. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Tube / Quick ± Connect Fittings 6C±8. . . . . . .
Precautions 6C±8. . . . . . . . . . . . . . . . . . . . . . . . . . .
Cautions During Work 6C±8. . . . . . . . . . . . . . . . . .
Removal 6C±8. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reuse of Quick±Connector 6C±10. . . . . . . . . . . . . . .
Assembling Advice 6C±10. . . . . . . . . . . . . . . . . . . . . .
Fuel Gauge Unit 6C±11. . . . . . . . . . . . . . . . . . . . . . . .
Fuel Gauge Unit and Associated Parts 6C±11. . .
Removal 6C±11. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation 6C±11. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Filler Cap 6C±12. . . . . . . . . . . . . . . . . . . . . . . . . .
General Description 6C±12. . . . . . . . . . . . . . . . . . . . .
Inspection 6C±12. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Main Data and Specifications 6C±12. . . . . . . . . . . . .
Service Precaution
WARNING: I F S O E Q U IPPED WITH A
SUPPLEMENTAL RESTRAINT SYSTEM (SRS),
REFER TO THE SRS COMPONENT AND WIRING
LOCATION VIEW IN ORDER TO DETERMINE
WHETHER YOU ARE PERFORMING SERVICE ON OR
NEAR THE SRS COMPONENTS OR THE SRS
WIRING. WHEN YOU ARE PERFORMING SERVICE
ON OR NEAR THE SRS COMPONENTS OR THE SRS
WIRING, REFER TO THE SRS SERVICE
INFORMATION. FAILURE TO FOLLOW WARNINGS
COULD RESULT IN POSSIBLE AIR BAG
DEPLOYMENT, PERSONAL INJURY, OR
OTHERWISE UNNEEDED SRS SYSTEM REPAIRS.
CAUTION: Always use the correct fastener in the
proper location. When you replace a fastener, use
ONLY the exact part number for that application.
ISUZU will call out those fasteners that require a
replacement after removal. ISUZU will also call out
the fasteners that require thread lockers or thread
sealant. UNLESS OTHERWISE SPECIFIED, do not
use supplemental coatings (Paints, greases, or other
corrosion inhibitors) on threaded fasteners or
fastener joint interfaces. Generally, such coatings
adversely affect the fastener torque and the joint
clamping force, and may damage the fastener. When
you install fasteners, use the correct tightening
sequence and specifications. Following these
instructions can help you avoid damage to parts and
systems.

6C±2
ENGINE FUEL
General Description
140RW030
Legend
(1) Fuel Filler Cap
(2) Fuel Tank
(3) Rollover Valve
(4) Fuel Pump
(5) Fuel Filter
(6) Fuel Rail Right
(7) Right Bank(8) Fuel Rail Left
(9) Left Bank
(10) Fuel Pressure Control Valve
(11) Common Chamber
(12) Duty Solenoid Valve
(13) Throttle Valve
(14) Canister
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
extinguisher near the work area.
Replace all pipes with the same pipe and fittings that
were removed.

Clean and inspect ªOº rings. Replace if 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±3
ENGINE FUEL

Adhere to all Notices and Cautions.
All gasoline engines are designed to use only unleaded
gasoline. Unleaded gasoline must be used for proper
emission control system operation.
Its use will also minimize spark plug fouling and extend
engine oil life. Using leaded gasoline can damage the
emission control system and could result in loss of
emission warranty coverage.
All cars are equipped with an Evaporative Emission
Control System. The purpose of the system is to minimize
the escape of fuel vapors to the atmosphere.
Fuel Metering
The Engine Control Module (ECM) is in complete control
of this fuel delivery system during normal driving
conditions.
The intake manifold function, like that of a diesel, is used
only to let air into the engine. The fuel is injected by
separate injectors that are mounted over the intake
manifold.
The Manifold Absolute Pressure (MAP) sensor measures
the changes in the intake manifold pressure which result
from engine load and speed changes, which the MAP
sensor converts to a voltage output.
This sensor generates the voltage to change
corresponding to the flow of the air drawn into the engine.
The changing voltage is transformed into an electric
signal and provided to the ECM.
With receipt of the signals sent from the MAP sensor,
Intake Air Temperature sensor and others, the ECM
determines an appropriate fuel injection pulse width
feeding such information to the fuel injector valves to
effect an appropriate air/fuel ratio.
The Multiport Fuel Injection system utilizes an injection
system where the injectors turn on at every crankshaft
revolution. The ECM controls the injector on time so that
the correct amount of fuel is metered depending on
driving conditions.
Two interchangeable ªOº rings are used on the injector
that must be replaced when the injectors are removed.
The fuel rail is attached to the top of the intake manifold
and supplies fuel to all the injectors.
Fuel is recirculated through the rail continually while the
engine is running. This removes air and vapors from the
fuel as well as keeping the fuel cool during hot weather
operation.
The fuel pressure control valve that is mounted on the fuel
rail maintains a pressure differential across the injectors
under all operating conditions. It is accomplished by
controlling the amount of fuel that is recirculated back to
the fuel tank based on engine demand.
See Section ªDriveability and Emissionº for more
information and diagnosis.

6C±4
ENGINE FUEL
Fuel Filter
Fuel Filter and Associated Parts
041RW014
Legend
(1) Fuel Filler Cap
(2) Fuel Hose(3) Fuel Filter Fixing Bolt
(4) Fuel Filter
Removal
CAUTION: When repair to the fuel system has been
completed, start engine and check the fuel system
for loose connection or leakage. For the fuel system
diagnosis, see Section ªDriveability and Emissionº.
1. Disconnect battery ground cable.
2. Remove Fuel filler cap(1).
3. Disconnect fuel hoses(2) from fuel filter on both
engine side and fuel tank side.
4. Fuel filter fixing bolt(3).

Remove the fuel filter fixing bolt(3) on fuel filter
holder.
5. Remove fuel filter(4).
Inspection
1. Replace the fuel filter if the fuel leaks from fuel filter
body or if the fuel filter body itself is damaged.
2. Replace the filter if it is clogged with dirt or sediment.
3. Check the drain of receive rubber and if it is clogged
with dust, clean it up with air.

6C±5
ENGINE FUEL
Installation
1. Install the fuel filter in the proper direction.
2. Install fuel filter holder fixing bolt.
3. Connect fuel hoses on engine side(1) and fuel tank
side(2).
041RW001
4. Install fuel filler cap
5. Connect the battery ground cable.
Inspection
After installation, start engine and check for fuel leakage.
In±Tank Fuel Filter
The filter is located on the lower end of fuel pickup tube in
the fuel tank. It prevents dirt from entering the fuel pipe
and also stops water unless the filter is completely
submerged in the water. It is a self cleaning type, not
requiring scheduled maintenance. Excess water and
sediment in the tank restricts fuel supply to the engine,
resulting in engine stoppage. In such a case, the tank
must be cleaned thoroughly.
Fuel Pump Flow Test
If reduction of fuel supply is suspected, perform the
following checks:
1. Make sure that there is fuel in the tank.
2. With the engine running, check the fuel feed pipe and
hose from fuel tank to injector for evidence of
leakage. Retighten, if pipe or hose connection is
loose. Also, check pipes and hoses for squashing or
clogging.
3. Insert the hose from fuel feed pipe into a clean
container, and check for fuel pump flow rate.4. Connect the pump relay terminals with a jumper
wire(1) as shown and start the fuel pump to measure
delivery.
140RW002
CAUTION: Never generate sparks when connecting
a jumper wire.
Delivery
Delivery
15 seconds0.38 liters minimum
If the measure value is out of standard, conduct the
pressure test.
Pressure test
For the pressure test to the fuel system, see Section 6E
ªFuel Control Systemº.

6C±6
ENGINE FUEL
Fuel Pump
Fuel Pump and Associated Parts
035RW047
Removal
CAUTION: When repair to the fuel system has been
completed, start engine and check the fuel system
for loose connection or leakage. For the fuel system
diagnosis, see Section ªDriveability and Emissionº.
1. Disconnect battery ground cable.
2. Loosen fuel filler cap.
3. Drain fuel.
Tighten drain plug to the specified torque after
draining fuel.
Torque: 20 N´m (2.0 Kg´m/14 lb ft) Ð M8
4. Remove fuel tank assembly(1). Refer to ªFuel Tank
Removalº in this section.
5. Remove fuel pump (FP) assembly(2) fixing screws
and remove the FP assembly.
NOTE: After removing FP, cover fuel tank to prevent any
dust entering.
Installation
1. Install FP assembly(2).
2. Install fuel tank assembly(1). Refer to ªFuel Tank
Installationº.
3. Fill the tank with fuel and tighten fuel filler cap.
4. Connect battery ground cable.

6C±7
ENGINE FUEL
Fuel Pump Relay
General Description
In order to control the FP operation, the FP relay is
provided. When the starter switch is turned to ªONº
position, the FP relay operates the FP for 2 seconds.When it is turned to ªSTARTº position, the Power Train
Control Module (PCM) receives the reference pulse from
the Ignition Control Module and it operates the relay,
again causing the FP to feed fuel.
Fuel Tank
Fuel Tank and Associated Parts
035RW048
Legend
(1) Fender Liner
(2) Fuel Filler Hose and Air Breather Hose and
Evapo Hose
(3) Undercover(4) Fuel Tank Wiring Connector
(5) Evapo Fuel Hose
(6) Fuel Feed Tube and Fuel Return
Tube/Quick±Connect Fittings
(7) Fuel Tank
Removal
CAUTION: When repair to the fuel system has been
completed, start engine and check the fuel system
for loose connection or leakage. For the fuel system
diagnosis, see Section ªDriveability and Emissionº.
1. Disconnect battery ground cable.
2. Loosen fuel filler cap.3. Drain fuel.
Tighten drain plug to the specified torque after
draining fuel.
Torque: 20 N´m (2.0 Kg´m/14 lb ft) Ð M8
4. Remove fender liner (1) of wheel well on rear right
side.
5. Fuel filler hose, air breather hose and evapo hose (2).
6. Remove undercover fixing bolts on both sides and
remove under cover(3).

6C±8
ENGINE FUEL
7. Disconnect two fuel tank wiring connectors(4) on
front right side of tank.
8. Disconnect evapo fuel hose(5).
9. Disconnect fuel feed tube and fuel return tube(6).
NOTE: Handling of the fuel tube, be sure to refer ªFuel
Tube/Quick±Connect Fittingsº in this section.
10. Remove fuel tank fixing bolts on both sides and
remove fuel tank(7).
Installation
1. Install fuel tank(7).

Place a flange on right side of tank on the bracket.
Install a flange on left side on the bracket from the
bottom, and tighten bolts to the specified torque.
Torque: 36 N´m (3.7 Kg´m/27 lb ft)
2. Connect fuel feed tube and fuel return tube(6).
3. Connect evapo fuel hose(5).
4. Connect fuel tank wiring connector(4).
5. Install undercover(3).
6. Connect fuel filler hose, air breather hose and evapo
hose(2).
7. Install fender liner(1).

Mount fender liner to the wheel well.

Fill the tank with fuel and tighten fuel filler cap.

Connect battery ground cable.
Fuel Tube / Quick ± Connect Fittings
Precautions

Lighting of Fires Prohibited.

Keep flames away from your work area to prevent the
inflammable from catching fire.

Disconnect the battery negative cable to prevent
shorting during work.

When welding or conducting other heat-generating
work on other parts, be sure to provide pretreatment
to protect the piping system from thermal damage or
spattering.
Cautions During Work
Do not expose the assembly to battery electrolyte or do
not wipe the assembly with a cloth used to wipe off spilt
battery electorolyte.
The piping wet with battery electrolyte cannot be used.
Be careful not to give a bending or twisting force to the
piping during the work. If deformed, replace with a new
piping.
Removal
1. Open the fuel cap to relieve the fuel pressure in the
tank.
If the fuel quick-connect fittings are dusty, clean with
an air blower, etc. and then remove it.
141RW016As some pressure may remain in the piping, cover the
connector with a cloth, etc. to prevent the splashing
of fuel in the first disconnection of the piping.