Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 370

6E–510

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Surges and/or Chuggles Symptom

  (Cont'd)

Step

No

Yes

Value(s)

Action

10

1. Check items that can cause the engine to run lean.

Refer to 

Diagnostic Aids in DTC P0171.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Go to 

Step 11

Verify repair

11

1. Check for proper ignition voltage output with spark

tester J 26792 (ST-125).  Refer to 

Electric Ignition

System for procedure.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 12

12

1. Check for a loose ignition coil ground and ION

Sensing module circuit.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 13

13

1. Check the ignition coils for cracks or carbon

tracking.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 15

14

1. Remove the spark plugs and check for wet plugs,

cracks, wear, improper gap, burned electrodes, or
heavy deposits.  Refer to 

Electronic Ignition

System.

NOTE: If spark plugs are gas or oil fouled, the cause of
the fouling must be determined before replacing the
spark plugs.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 15

15

1. Check the injector connections.
2. If any of the injector connectors are connected to an

incorrect cylinder, correct as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 16

16

1. Check PCM grounds for the cleanliness, tightness

and proper locations.  Refer to the PCM wiring
diagrams in 

Electrical Diagnosis.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 17

17

1. Check MAF sensor connections.
2. If a problem is found, replace the faulty terminals as

necessary.  Refer to 

Electrical Diagnosis for wiring

repair procedures.

Was a problem found?

—

Verify repair

Go to 

Step 18

18

1. Visually/physically check vacuum hoses for splits,

kinks, and proper connections and routing as
shown on the “Vehicle Emission Control
Information” label.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 19

6E–511

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Surges and/or Chuggles Symptom

  (Cont'd)

Step

No

Yes

Value(s)

Action

19

1. Check the exhaust system for possible restriction:

D

Inspect the exhaust system for damaged or
collapsed pipes.

D

Inspect the muffler for heat distress or possible
internal failure.

D

Check for a possible plugged three-way
catalytic converter by checking the exhaust
system back pressure.  Refer to 

Restricted

Exhaust System Check.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 20

20

1. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no

malfunctions have been found, review/inspect the
following:

D

Visual/physical inspection

D

Tech 2 data

D

Freeze Frame data/Failure Records buffer

D

All electrical connections within a suspected
circuit and/or system.

3. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Contact

Technical

Assistance

6E–512

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Lack of Power, Sluggish, or Spongy Symptoms

 

Step

Action

Value(s)

Yes

No

1

DEFINITION:
Engine delivers less than expected power.  Little or no
increase in speed when accelerator pedal is pushed
down part-way.

Was the “On-Board Diagnostic (OBD) System Check”
performed?

—

Go to 

Step 2

Go to 

OBD

System

Check

2

Was the “Electric Throttle Control (ETC) System
Check” performed?

—

Go to 

Step 3

Go to 

ETC

System

Check

3

1. Perform a bulletin search.
2. If a bulletin that addresses the symptom is found,

correct the condition as instructed in the bulletin.

Was a bulletin found that addresses the symptom?

—

Verify repair

Go to 

Step 4

4

Was a visual/physical check performed?

—

Go to 

Step 5

Go to 

Visual/

Physical

Check

5

1. Remove and check the air filter element for dirt or

restrictions.  Refer to 

Air Intake System in

ON-Vehicle Service.

2. Replace the air filter element if necessary.

Was a repair required?

—

Verify repair

Go to 

Step 6

6

1. Check for low fuel pressure.  Refer to 

Fuel System

Pressure Test.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 7

7

1. Check for water- or alcohol-contaminated fuel.
2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 8

8

1. Install the Tech 2.
2. Run the engine at idle.
3. On the Tech 2, select F3: Miscellaneous Test, F6:

Variable Intake Manifold.

4. Repeat Switch ON or OFF of VIM solenoid valve by

using the Tech 2.

5. Check to see if the actuator works normally.
6. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 9

9

1. Check for proper ignition voltage output with spark

tester J 26792 (ST-125).  Refer to 

Electronic Ignition

System for procedure.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 10

6E–513

6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Lack of Power, Sluggish, or Spongy Symptoms

  (Cont'd)

Step

No

Yes

Value(s)

Action

10

1. Remove the spark plugs and check for wet plugs,

cracks, wear, improper gap, burned electrodes, or
heavy deposits.  Refer to 

Electronic Ignition

System.

NOTE: If spark plugs are gas or oil fouled, the cause of
the fouling must be determined before replacing the
spark plugs.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 11

11

1. Check the ignition coils for cracks or carbon

tracking.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 12

12

1. Check the PCM grounds for cleanliness, tightness

and proper locations.  Refer to the PCM wiring
diagrams in 

Electrical Diagnosis.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 13

13

1. Check the exhaust system for possible restriction:

D

Inspect the exhaust system for damaged or
collapsed pipes.

D

Inspect the muffler for heat distress or possible
internal failure.

D

Check for a possible plugged three-way
catalytic converter by checking the exhaust
system back pressure.  Refer to 

Restricted

Exhaust System Check.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 14

14

1. Check the torque converter clutch (TCC) for proper

operation.  Refer to 

4L30-E Transmission

Diagnosis.

2. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Go to 

Step 15

15

1. 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?

—

Verify repair

Go to 

Step 16

16

1. Review all diagnostic procedures within this table.
2. If all procedures have been completed and no

malfunctions have been found, review/inspect the
following:

D

Visual/physical inspection

D

Tech 2 data

D

Freeze Frame data/Failure Records buffer

D

All electrical connections within a suspected
circuit and/or system.

3. If a problem is found, repair as necessary.

Was a problem found?

—

Verify repair

Contact

Technical

Assistance