1998 ISUZU TROOPER removing engine

6A±52
ENGINE MECHANICAL
Cylinder Head
Cylinder Head and Associated Parts
011RW008
Legend
(1) Spark Plug
(2) Cylinder Head Bolt
(3) Camshaft Drive Gear Pulley Fixing Bolt
(4) Camshaft Drive Gear Pulley
(5) Camshaft Bracket Fixing Bolt
(6) Camshaft Bracket
(7) Camshaft Exhaust(8) Camshaft Intake
(9) Retainer Fixing Bolt
(10) Retainer Assembly
(11) Tappet with Shim
(12) Split Collar
(13) Valve Spring and Spring Upper Seat
(14) Valve
Disassembly
NOTE:

During disassembly, be sure that the valve train
components are kept together and identified so that
they can be reinstalled in their original locations.
Before removing the cylinder head from the engine
and before disassembling the valve mechanism,
perform a compression test and note the results.
1. Remove camshaft drive gear pulley fixing bolt (3),
then pulley (4).

6A±57
ENGINE MECHANICAL
5. Use 5±8840±2446±0 valve spring compressor and
5±8840±2547±0 valve spring compressor adapter to
remove split collar.
014RW042
6. Remove valve spring.
7. Remove valve.
8. Remove oil controller and spring lower seat.
9. Remove the valve guide using the 5±8840±2442±0
valve guide replacer.
Inspection and Repair
Valve Spring
CAUTION: Visually inspect the valve springs and
replace them if damage or abnormal wear is evident.
1. Measure the free height of the springs. The springs
must be replaced if the free height is below the
specified limit.
Standard : 44.6 mm (1.7559 in)
Limit : 43.6 mm (1.7165 in)
014RS004
2. Measure the valve spring squareness with a steel
square and replace the valve springs if the measured
value exceeds the specified limit.
Limit : 2 mm (0.0787 in)
014RS005
3. Using a spring tester to compress the springs to the
installed height, measure the compressed spring
tension, and replace the springs if the measured
tension is below the specified limit.
At installed height: 35.0 mm (1.38 in)
Standard: 196 N (44 lb)
Limit: Less than 181 N (41 lb)
014RS006
Valve Guide
CAUTION: Take care not to damage the valve seat
contact surface, when removing carbon adhering to
the valve head. Carefully inspect the valve stem for
scratchs or abnormal wear. If these conditions are
present, the valve and the valve guide must be
replaced as a set.

6A±77
ENGINE MECHANICAL
Piston and Connecting Rod
Piston, Connecting Rod and Associate Parts
015RW019
Legend
(1) Cylinder Head Assembly
(2) Cylinder Head Gasket
(3) Crankcase with Oil Pan
(4) Oil Pipe and O-Ring
(5) Oil Strainer and O-Ring
(6) Oil Gallery(7) Piston and Connecting Rod Assembly
(8) Piston Ring
(9) Piston Pin
(10) Piston
(11) Connecting Rod
(12) Connecting Rod Cap
Disassembly
1. Remove cylinder head assembly (1). Refer to
ªCylinder Head Removalº in this manual.
2. Remove cylinder head gasket (2).
3. Remove crankcase with oil pan (3). Refer toªOil Pan
and Crankcaseº in this manual.
4. Remove oil pipe and O-ring (4).5. Remove oil strainer and O-ring (5).
6. Remove oil gallery (6).
7. Remove connecting rod cap with connecting rod
lower bearing (12).
8. Remove piston and connecting rod assembly (7).
NOTE: Before removing piston and connecting rod
assembly, measure thrust clearance.

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±9
ENGINE FUEL
2. For removal of the delivery pipe (feeding fuel to the
engine), hold the connector in one hand, and hold the
retainer tab with the other hand and pull out the
connector, as illustrated. The pipe can be removed
with the retainer attached.
141RW019
3. For removal of the return pipe (returning fuel to the
tank), hold the pipe in one hand, and pull out the
connentor with the other hand while pressing the
square relieve button of the retainer, as illustrated.
141RW020
NOTE: This work should be done by hands. Do not use
any tools. Should the pipe can hardly be removed from
the connector, use a lubricant (light oil) and/or push and
pull the connector longitudinally until the pipe is removed.
141RW021When reusing the delivery pipe retainer, reuse
without removing the retainer from the pipe. If the
retainer is damaged or deformed, however, replace
with a new retainer.
Cover the connectors removed with a plastic bag, etc.
to prevent the entry of dust or rain water.
141RW022

6C±11
ENGINE FUEL
Fuel Gauge Unit
Fuel Gauge Unit and Associated Parts
140RS004
Legend
(1) Wiring Connector
(2) Fuel Gauge Unit
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. Wiring connector

Disconnect wiring connector(1) from the unit.
5. Fuel gauge unit

Remove the fixing screws, then the fuel gauge
unit(2).
NOTE: After removing fuel gauge unit, cover fuel tank to
prevent any dust entering
Installation
1. Fuel gauge unit(2).
2. Wiring connector(1).

Connect the wiring connector to the fuel gauge unit.

Fill the tank with fuel and tighten fuel filler cap.

Connect battery ground cable.

6E±80
ENGINE DRIVEABILITY AND EMISSIONS
Circuit Description
The electronic Ignition system uses a coil-at-plug method
of spark distribution. In this type of ignition system, the
powertrain control module (PCM) triggers the correct
driver inside the ignition coil, which then triggers the
correct ignition coil based on the 58X signal received from
the crankshaft position sensor (CKP). The spark plug
connected to the coil fires when the ICM opens the ground
circuit for the coil's primary circuit.
During crank, the PCM monitors the CKP 58X signal. The
CKP signal is used to determine which cylinder will fire
first. After the CKP 58X signal has been processed by the
PCM, it will command all six injectors to allow a priming
shot of fuel for all the cylinders. After the priming, the
injectors are left ªOFFº during the next six 58X reference
pulses from the CKP. This allows each cylinder a chance
to use the fuel from the priming shot. During this waiting
period, a camshaft position (CMP) signal pulse will have
been received by the PCM. The CMP signal allows the
PCM to operate the injectors sequentially based on
camshaft position. If the camshaft position signal is not
present at start-up, the PCM will begin sequential fuel
delivery with a 1-in-6 chance that fuel delivery is correct.
The engine will run without a CMP signal, but will set a
DTC code.
Diagnostic Aids
An intermittent problem may be caused by a poor
connection, rubbed-through wire insulation or a wire
broken inside the insulation. Check for the following
items:

Poor connection or damaged harness ± Inspect the
PCM harness and connectors for improper mating,
broken locks, improperly formed or damaged
terminals, poor terminal-to-wire connection, and
damaged harness.

Faulty engine coolant temperature sensor ± Using
Tech 2, compare engine coolant temperature with
intake air temperature on a completely cool engine.
Engine coolant temperature should be within 10
C of
intake air temperature. If not, replace the ECT sensor.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
5. An obvious cause of low fuel pressure would be an
empty fuel tank.
6. The engine will easily start and run if a few injectors
are disabled. It is not necessary to test all injectors
at this time since this step is only a test to verify that
all of the injectors have not been disabled by fuel
contamination.
7. A blinking test light verifies that the PCM is
monitoring the 58X crankshaft reference signal and
is capable of activating the injectors. If there is an
open or shorted driver circuit, DTCs 201-206 should
be set.
19.By using a spark tester, each ignition coil's ability to
produce 25,000 volts is verified.
25.If there is an open or shorted driver circuit, DTCs
201-206 should be set. All six injector driver circuits
can be checked at one time without removing the
intake manifold if a 5-8840-2636-0 test light is
available. This is the alternative procedure:

With the ignition ªOFF,º disconnect the gray
connector located at the rear of the air filter, attached
to a bracket on the purge canister.

Connect test light 5-8840-2636-0 to the connector.
Do any of the light constantly illuminate or fail to blink
when the engine is cranked? If so, repair the short or
open circuit, or replace the PCM if indicated.
This procedure only tests the driver circuit as far as the
test connection, so step 31 is added to test the circuit all
the way to the injector.

6E±86
ENGINE DRIVEABILITY AND EMISSIONS
CAUTION: To reduce the risk of fire and personal
injury:

It is necessary to relieve fuel system pressure
before connecting a fuel pressure gauge. Refer to
Fuel Pressure Relief Procedure, below.

A small amount of fuel may be released when
disconnecting the fuel lines. Cover fuel line
fittings with a shop towel before disconnecting, to
catch any fuel that may leak out. Place the towel in
an approved container when the disconnect is
completed.Fuel Pressure Relief Procedure
1. Remove the fuel cap.
2. Remove the fuel pump relay from the underhood
relay center.
3. Start the engine and allow it to stall.
4. Crank the engine for an additional 3 seconds.
Fuel Gauge Installation
1. Remove the shoulder fitting cap.
2. Install fuel gauge 5-8840-0378-0 to the fuel feed line
located in front of and above the right side valve train
cover .
3. Reinstall the fuel pump relay.
Fuel System Electrical Test

StepActionValue(s)Ye sNo
1Was the ªOn-Board Diagnostic (OBD) System Checkº
performed?
ÐGo to Step 2
Go to OBD
System
Check
21. Read the ªCautionº above.
2. Relieve the fuel system pressure and install the fuel
pump pressure gauge to the test fitting.
3. Use Tech 2 to command the fuel pump ªON.º
Is there an immediate pressure build-up which
indicates the pump is running?
ÐGo to Step 3Go to Step 4
31. Verify that the pump is not running by removing the
fuel filler cap and listening.
2. Command the pump ªONº with Tech 2.
Did the pump turn ªOFFº after 2 seconds?
Ð
Test
completed
Go to Step 12
41. Ignition ªOFF.º
2. Remove the fuel pump relay.
3. Using a test light connected to ground, probe the
battery feed to the relay.
Did the light illuminate?
ÐGo to Step 6Go to Step 5
5Repair short or open battery feed to fuel pump relay.
Is the action complete?
ÐVerify repairÐ
61. Connect a test light between the two wires that
connect to the fuel pump relay pull-in coil.
2. Ignition ªON.º
Did the test light illuminate for 2 seconds and then turn
off?
ÐGo to Step 12Go to Step 7
71. With a test light connected to battery (±), probe the
fuel pump relay connector at the wire which runs
from the relay pull-in coil to the PCM.
2. Ignition ªON.º
Did the test light illuminate for 2 seconds and then turn
off?
ÐGo to Step 8Go to Step 9
8Locate and repair open in the fuel pump relay ground
circuit.
Is the action complete?
ÐVerify repairÐ