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Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 870

6E–209

3.2L ENGINE DRIVEABILITY AND EMISSIONS

Cuts Out, Misses Symptom

Step

Action

Value(s)

Yes

DEFINITION:
Steady pulsation or jerking that follows engine speed;
usually more pronounced as engine load increases.

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

—

Go to

Step 2

Go to

OBD

System

Check

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?

—

Go to

Step 13

Go to

Step 3

Was a visual/physical check performed?

—

Go to

Step 4

Go to

Visual/Physic

al Check

1. Check the ECM grounds for clearness, tightness

and proper routing. Refer to the ECM wiring
diagrams in

Electrical Diagnosis.

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

Was a problem found?

—

Verify repair

Go to

Step 5

Observe the long term fuel trim on the Tech 2.

Is the long term fuel trim significantly in the negative
range (rich condition)?

—

Go to

Step 6

Go to

Step 7

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

Refer to

Diagnostic Aids in DTC P0172 Diagnostic

Support.

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

Was a problem found?

—

Verify repair

Go to

Step 9

Is the long term fuel trim significantly in the positive
range (lean condition)?

—

Go to

Step 8

Go to

Step 9

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

Refer to

Diagnostic Aids in DTC P0171 Diagnostic

Support.

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

Was a problem found?

—

Verify repair

Go to

Step 9

1. Check for incorrect idle speed. Ensure that the

following conditions are present:

The engine is fully warm.

The accessories are “off.”

2. Using a Tech 2, monitor the IAC position.

Is the IAC position within the specified values?

Between 5

and 50

counts

Go to

Step 11

Go to

Step 10

6E–210 3.2L ENGINE DRIVEABILITY AND EMISSIONS

Cuts Out, Misses Symptom

(Cont'd)

Step

Yes

Value(s)

Action

1. Visually/physically inspect for the following

conditions:

Restricted air intake system. Check for a

possible collapsed air intake duct, restricted
air filter element, or foreign objects blocking

the air intake system.

Throttle body. Check for objects blocking the

IAC passage or throttle bore, excessive
deposits in the IAC passage and on the IAC
pintle, and excessive deposits in the throttle

bore and on the throttle plate.

Large vacuum leak. Check for a condition that

causes a large vacuum leak, such as an
incorrectly installed or faulty PCV valve or

brake booster hose disconnected .

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

Was a problem found?

—

Verify repair

Go to

Step 8

Check the injector connections. If any of the injectors
are connected to an incorrect cylinder, correct as
necessary.

Was a problem found?

—

Verify repair

Go to

Step 12

1. Perform the “Injector Coil/Balance Test” in

Fuel

Metering System.

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

Was a problem found?

—

Verify repair

Go to

Step 13

1. Check for fuel in the pressure regulator vacuum

hose.

2. If fuel is present, replace the fuel pressure regulator

assembly. Refer to

Fuel Metering System.

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

Was a problem found?

—

Verify repair

Go to

Step 14

1. Check for proper ignition voltage output with spark

tester 5-8840-0383-0. Refer to

Electronic Ignition

System for the procedure.

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

Was a problem found?

—

Verify repair

Go to

Step 15

1. Remove spark plugs. 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 16

1. Check for a loose ignition coil ground.

Refer to

Electronic Ignition System.

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

Was a problem found?

—

Verify repair

Go to

Step 17

6E–211

3.2L ENGINE DRIVEABILITY AND EMISSIONS

Cuts Out, Misses Symptom

(Cont'd)

Step

Yes

Value(s)

Action

1. Check 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 18

Using a Tech 2, monitor the TP angle with the engine
idling.

Is the TP angle at the specified value and steady?

Go to

Step 19

Refer to

DTC

P0123 for

further

diagnosis

1. Check the PCV valve for proper operation. Refer to

Crankcase Ventilation System.

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

Was a problem found?

—

Verify repair

Go to

Step 20

1. Check the transmission range switch circuit. Use a

Tech 2 and be sure the Tech 2 indicates that the
vehicle is in drive with the gear selector in drive or
overdrive.

2. If a problem is found, diagnose and repair the

transmission range switch as necessary.

Was a problem found?

—

Verify repair

Go to

Step 21

1. 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?

—

Verify repair

Go to

Step 22

1. 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?

—

Verify repair

Go to

Step 23

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:

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?

—

Verify repair

Contact

Technical

Assistance

6E–212 3.2L ENGINE DRIVEABILITY AND EMISSIONS

Hesitation, Sag, Stumble Symptom

Step

Action

Value(s)

Yes

DEFINITION:
Momentary lack of response as the accelerator is
pushed down. Can occur at any vehicle speed. Usually
most pronounced when first trying to make the vehicle
move, as from a stop sign. May cause the engine to stall
if severe enough.

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

—

Go to

Step 2

Go to

OBD

System

Check

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 3

Was a visual/physical check performed?

—

Go to

Step 4

Go to

Visual/Physic

al Check

1. Check the fuel control heated oxygen sensors

(HO2S). The fuel control heated oxygen sensors
(HO2S) should respond quickly to different throttle
positions. If they don’t, check them for silicon or
other contaminants from fuel or use of improper
RTV sealant. The sensors may have a white
powdery coating.

Silicon contamination causes a high but false
HO2S signal voltage (rich exhaust indication).
The ECM will then reduce the amount of fuel
delivered to the engine, causing a severe
driveability problem. For more information, refer
to

Engine Control Module (ECM) and Sensors.

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

Was a problem found?

—

Verify repair

Go to

Step 5

1. Check the 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 6

Observe the TP angle display on the Tech 2 while
slowly increasing throttle pedal.

Does the TP angle display steadily increase from 0% at
closed throttle to 100% at WOT?

—

Go to

Step 7

Go to

Step 18

Monitor the long term fuel trim on the Tech 2.

Is the long term fuel trim significantly in the negative
range (rich condition)?

—

Go to

Step 8

Go to

Step 9

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

Refer to

Diagnostic Aids in DTC P0172 Diagnostic

Support.

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

Was a problem found?

—

Verify repair

Go to

Step 10

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

Refer to

Diagnostic Aids in DTC P0171 Diagnostic

Support.

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

Was a problem found?

—

Verify repair

Go to

Step 10

Content .. 868 869 870 871 ..