Isuzu Trooper (1998-2002 year). Manual - part 638

6E–200

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

Symptoms

Initial Diagnosis

Default Section(s)

Hesitation, Sag, Stumble

1. OBD system check.
2. AP.
3. MAP output check.
4. Fuel system diagnosis.
5. Injector system.

Generator Output Voltage (refer
to 

Chassis Electrical),

Calibration ID/Service Bulletins,
Ignition System Check

Rough, Unstable, or Incorrect Idle,
Stalling

1. OBD system check.
2. Fuel injector test.

MAP Output Check, Throttle
Linkage, A/C Clutch Control
Circuit Diagnosis, Calibration
ID/Service Bulletins, Generator
Output Voltage (refer to 

Chassis

Electrical), Exhaust Diagnosis

Poor Fuel Economy

1. OBD system check.
2. Careful visual/physical inspection.
3. Injector system.
4. Cooling system.

TCC Operation, Exhaust
System (refer to 

Engine

Exhaust)

Engine Cranks But Will Not Run

1. OBD system check.

Fuel System Electrical
Diagnosis, Fuel System
Diagnosis, Fuel Injector Test.

Excessive Exhaust Emissions or
Odors

1. OBD system check.
2. Emission test.
3. Cooling system.
4. Fuel system diagnosis.
5. Fuel injector test.
6. Injector system.
7. MAP output check.

Exhaust Diagnosis, Calibration
ID/Service Bulletins

Dieseling, Run-On

1. OBD system check.
2. Careful visual/physical inspection.
3. Fuel system diagnosis.

—

6E–201

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

On–Vehicle Service

 Camshaft Position (CMP)

Sensor

Removal Procedure

1. Disconnect the negative battery cable.
2. Disconnect the electrical connector to the CMP

sensor.

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3. Remove the CMP sensor retaining bolt from the

cylinder head cover.

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Inspection Procedure

1. Inspect the sensor O-ring for cracks or leaks.
2. Replace the O-ring if it is worn or damaged.
3. Lubricate the new O-ring with engine oil.
4. Install the lubricated O-ring.

Installation Procedure

1. Install the CMP sensor in the cylinder head cover.
2. Install the CMP sensor retaining bolt.

Tighten

D

Tighten the retaining bolt to 9 N·m (78 lb in.).

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3. Connect the electrical connector to the CMP sensor.

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4. Connect the negative battery cable.

6E–202

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

Crankshaft Position (CKP)

Sensor

Removal Procedure

1. Disconnect the negative battery cable.
2. Remove the under cover.

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3. Disconnect the electrical connector to the CKP

sensor.

4. Remove one bolt and the CKP sensor from the left

side of the engine block.

NOTE: Use caution to avoid any hot oil that might drip
out.

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Inspection Procedure

1. Inspect the sensor O-ring for cracks or leaks.
2. Replace the O-ring if it is worn or damaged.
3. Lubricate the new O-ring with engine oil.
4. Install the lubricated O-ring.

Installation Procedure

1. Install the CKP sensor in the engine block.
2. Install the CKP sensor mounting bolt.

Tighten

D

Tighten the mounting bolt to 9 N·m (78 lb in.).

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3. Connect the electrical connector to the CKP sensor.
4. Install the under cover.

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5. Connect the negative battery cable.

6E–203

4JX1–TC ENGINE DRIVEABILITY AND EMISSIONS

Engine Coolant Temperature

(ECT) Sensor

Removal Procedure

NOTE: Care must be taken when handling the engine
coolant temperature (ECT) sensor.  Damage to the ECT
sensor will affect proper operation of the fuel injection
system.

1. Disconnect the negative battery cable.
2. Drain the radiator coolant.  Refer to 

Draining and

Refilling Cooling System in Engine Cooling.

3. Disconnect the electrical connector.
4. Remove the ECT sensor from the front side of the

intake manifold.

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Installation Procedure

1. Apply sealer (LOCTITE 262) or the equivalent to the

threads of the ECT sensor.

2. Install the ECT sensor in the front side of the intake

manifold.

Tighten

D

Tighten the ECT sensor to 19 N·m (14 lb ft.).

3. Connect the electrical connector.

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4. Fill the radiator with coolant.  Refer to 

Draining and

Refilling Cooling System in Engine Cooling.

5. Connect the negative battery cable.

Intake Air Temperature (IAT)

Sensor

Removal Procedure

1. Disconnect the negative battery cable.
2. Disconnect the electrical connector from the IAT

sensor.

3. Remove the IAT sensor from the intake air duct by

using a rocking motion while pulling the sensor.

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