Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 181

6E–328

4JH1 ENGINE DRIVEABILITY AND EMISSIONS

34

Replace the injection pump assembly. 
Is the action complete?

—

Verify repair

—

Step

Action

Value(s)

Yes

No

4JH1 ENGINE DRIVEABILITY AND EMISSIONS

6E–329

CUTS OUT, MISSES SYMPTOM

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

time

rpm

Step

Action

Value(s)

Yes

No

1

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

—

Go to Step 2

Go to On Board 

Diagnostic 

(OBD) System 

Check

2

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

3

Was a visually/physical check performed?

—

Go to Step 4

Go to Visual / 

physical Check

4

Is the customer using the incorrect fuel type? 

Diesel fuel 

only

Replace with 

diesel fuel

Go to Step 5

5

Visually/physically inspect for the following conditions. 

• Restrict air intake system. Check for a restricted air

filter element, or foreign objects blocking the air
intake system 

• Check for objects blocking or excessive deposits in

the throttle bore and on the throttle plate 

• Check for a condition that causes a large vacuum

leak, such as an incorrectly installed or faulty
crankcase ventilation hose. 

• Restrict air intake system at the turbocharger.

Check for objects blocking the turbocharger
compressor 

wheel or turbine shaft sticking. 
If a problem is found, repair as necessary. 
Was a problem found?

—

Verify repair

Go to Step 6

6

Check the ECM & PSG grounds to verify that they are
clean and tight. Refer to the ECM wiring diagrams. 
Was a problem found?

—

Verify repair

Go to Step 7

6E–330

4JH1 ENGINE DRIVEABILITY AND EMISSIONS

7

1. Using the Tech 2, perform test drive. 

2. Monitor the “Vehicle Speed” in the data display. 

Does the Tech 2 indicate correct “Vehicle Speed”
depending on driving speed? 

—

Go to Step 11

Go to Step 8

8

Check the VSS harness for the following conditions. 

• Check for poor connector connection. 

• Check for misrouted harness. 

• Check for any accessory parts which may cause

electric interference. 

If a problem is found, repair as necessary. 
Was a problem found? 

—

Verify repair

Go to Step 9

9

Substitute a known good VSS and recheck. 
Was the problem solved?

—

Go to Step 10

Go to Step 31

10

Replace the VSS assembly. 
Is the action complete?

—

Verify repair

—

11

1. Using the Tech 2, ignition “On” and engine “Run”. 

2. Monitor the “Mass Air Flow” in the data display. 

Does the Tech 2 indicate correct “Mass Air Flow”
depending on accelerator pedal operation? 

—

Go to Step 16

Go to Step 12

12

Remove the MAF & IAT sensor assembly and check
for the following conditions. 

• Objects blocking at the MAF sensor element. 
If a problem is found, repair as necessary. 
Was the problem found?

—

Verify repair

Go to Step 13

13

Check the MAF sensor harness for the following
conditions. 

• Check for poor connector connection. 

• Check for misrouted harness. 

• Check for any accessory parts which may cause

electric interference. 

If a problem is found, repair as necessary. 
Was a problem found? 

—

Verify repair

Go to Step 14

14

Substitute a known good MAF & IAT sensor assembly
and recheck. 
Was the problem solved?

—

Go to Step 15

Go to Step 31

15

Replace the MAF & IAT sensor assembly. 
Is the action complete?

—

Verify repair

—

Step

Action

Value(s)

Yes

No

      When constant vehicle speed

                                                 

                                                 

High

Correct Speed

Low

Time

 Unstable Data

4JH1 ENGINE DRIVEABILITY AND EMISSIONS

6E–331

16

1. Using the Tech 2, ignition “On” and engine “Off”. 

2. Monitor the “Pedal/Throttle Position” and “Idle

Switch” in the data display. 

Does the Tech 2 indicate correct “Pedal/Throttle
Position” from 0% to 100% and correct “Idle Switch”
status depending on accelerator pedal operation?

—

Go to Step 21

Go to Step 17

17

1. Using the Tech 2, ignition “On” and engine “Off”. 

2. Monitor the “Pedal/Throttle Position” and “Idle

Switch” in the data display. 

3. Adjust the accelerator cable or TPS within 0% to

100%. 

Was the problem solved?

—

Verify repair

Go to Step 18

18

Check the TPS harness for the following conditions. 

• Check for poor connector connection. 

• Check for misrouted harness. 

• Check for any accessory parts which may cause

electric interference. 

If a problem is found, repair as necessary. 
Was a problem found? 

—

Verify repair

Go to Step 19

19

Substitute a known good TPS and recheck. 
Was the problem solved?

—

Go to Step 20

Go to Step 31

20

Replace the TPS. 
Is the action complete?

—

Verify repair

—

21

Remove the CKP sensor from the flywheel housing
and check for the following conditions. 

• Objects sticking the CKP sensor. 

• Objects sticking the CKP sensor pulser. 
If a problem is found, repair as necessary. 
Was the problem found? 

—

Verify repair

Go to Step 22

22

Check the CKP sensor harness for the following
conditions. 

• Check for poor connector connection. 

• Check for misrouted harness. 

• Check for any accessory parts which may cause

electric interference. 

If a problem is found, repair as necessary. 
Was a problem found? 

—

Verify repair

Go to Step 23

23

Substitute a known good CKP sensor and recheck. 
Was the problem solved?

—

Go to Step 24

Go to Step 25

24

Replace the CKP sensor. 
Is the action complete?

—

Verify repair

—

Step

Action

Value(s)

Yes

No