timing belt ISUZU TROOPER 1998 Service Workshop Manual

6E±50
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Engine Cranks But Will Not Run

 
StepNo Ye s Value(s) Action
10Refer to Engine Mechanical Diagnosis to diagnose the
following conditions:

Faulty camshaft drive belts

Leaking or sticky valves or rings

Excessive valve deposits

Weak valve springs

Incorrect valve timing

Leaking head gasket
Is the action complete?
ÐVerify repairGo to Step 11
11Observe the ªEngine Speedº data display on the Tech 2
while cranking the engine.
Is the engine RPM indicated? (If the Tech 2 is normally
powered from the cigarette lighter socket, and if the
Tech 2 display goes blank while cranking the engine, it
will be necessary to power the Tech 2 directly from the
vehicle battery.)
ÐGo to Step 12Go to Step 17
121. At the ECM (female) side of the connector
mentioned in step, connect a test light between the
ignition + terminal and one of the injector driver
circuits at the same connector.
2. Ignition ªON.º
3. Observe the test light, and repeat the test for each
injector driver circuit by oscilloscope.
Did the test light stay on when checking any of the 4
injector driver circuits?
ÐGo to Step 13Go to Step 15
131. Ignition ªOFF,º disconnect the ECM.
2. Ignition ªON,º observe the test light.
Is the test light ªON?º
ÐGo to Step 14Go to Step 16
14Locate and repair the short to ground in the injector
driver circuit.
Is the action complete?
ÐVerify repairÐ
15Check for an open injector driver circuit.
Was a problem found?
ÐVerify repairGo to Step 16
16Replace the ECM (Refer to the Data Programming in
Case of ECM change).
Is the action complete?
ÐVerify repairÐ
171. Raise the vehicle and disconnect the CKP sensor
harness.
2. Ignition ªON.º
3. With a test light to ground, probe the harness
ignition feed terminal.
Did the light illuminate?
ÐGo to Step 19Go to Step 18
18Check the ignition feed wire between the sensor and
the ECM for a short to ground or open circuit.
Is the action complete?
ÐVerify repairÐ

6E±182
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Lack of Power, Sluggish or Spongy Symptom

 
StepNo Ye s Value(s) Action
111. Check for an engine mechanical problem. Check
for low compression, incorrect or worn camshaft,
loose timing belt, etc. Refer to
Engine Mechanical.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 12
121. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no
malfunctions have been found, review/inspect the
following:

Visual/physical inspection

Tech 2 data

Freeze Frame data/Failure Records buffer

All electrical connections within a suspected
circuit and/or system.
3. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repair
Contact
Technical
Assistance

6E±184
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Rough, Unstable, or Incorrect Idle, Stalling Symptom

 
StepNo Ye s Value(s) Action
91. Check for the following engine mechanical items.
Refer to
Engine Mechanical for diagnosis
procedures:

Low compression

Sticking or leaking valves

Worn camshaft lobe(s)

Camshaft drive belt slipped or stripped

Incorrect valve timing

Valves clearance

Broken valve springs
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 10
101. Check for faulty engine mounts. Refer to Engine
Mechanical
for inspection of mounts.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 11
111. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no
malfunctions have been found, review/inspect the
following:

Visual/physical inspection

Tech 2 data

Freeze Frame data/Failure Records buffer

All electrical connections within a suspected
circuit and/or system.
3. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repair
Contact
Technical
Assistance

6E±190
4JX1±TC ENGINE DRIVEABILITY AND EMISSIONS
Cuts Out, Symptom

 
StepNo Ye s Value(s) Action
91. Injector Test
Operate the each injector by Tech 2 with the
ignition ªONº and check if the working noise
confirm.
2. If a problem is found, check the harness or replace
the injector.
Is the action complete?
ÐVerify repairGo to Step 10
101. Check the following engine mechanical items.
Refer to
Engine Mechanical for diagnosis
procedures:

Low compression

Sticking or leaking valves

Worn camshaft lobe(s)

Camshaft drive belt slipped or stripped

Incorrect valve timing

Broken valve springs
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 11
111. Check for faulty motor mounts. Refer to Engine
Mechanical
for inspection of mounts.
2. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repairGo to Step 12
121. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no
malfunctions have been found, review/inspect the
following:

Visual/physical inspection

Tech 2 data

Freeze Frame data/Failure Records butter

All electrical connections within a suspected
circuit and/or system
3. If a problem is found, repair as necessary.
Was a problem found?
ÐVerify repair
Contact
Technical
Assistance