Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 89

 

  Index      Ford     Isuzu D-Max / Isuzu Rodeo TFR/TFS series - service repair manual 1997-2003 year

 

Search            

 

 

 

 

 

 

 

  

 

Content   ..  87  88  89  90   ..

 

 

Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 89

 

 

4JA1-TC/4JH1-TC ENGINE DRIVEABILITY AND EMISSIONS

6E–351

HESITATION, SAG, STUMBLE SYMPTOM

DEFINITIONS: 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.

time

rpm

Sug

Hesitation

Stumble

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

Check the torque converter clutch (TCC) for proper
operation (if A/T model). If a problem is found, repair
as necessary. 
Was a problem found?

—

Verify repair

Go to Step 6

6

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 7

7

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 8

6E–352

4JA1-TC/4JH1-TC ENGINE DRIVEABILITY AND EMISSIONS

8

1. Using the Tech 2, display the ECT sensor and IAT

sensor value. 

2. Check the displayed value. 

Does the Tech 2 indicate correct temperature
depending on engine condition? 
If a problem is found, repair as necessary. 
Was the problem found?

—

Verify repair

Go to Step 9

9

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 14

Go to Step 10

10

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 11

11

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 12

12

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

—

Go to Step 13

Go to Step 31

13

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

—

Verify repair

—

14

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 19

Go to Step 15

15

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 16

16

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 17

17

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

—

Go to Step 18

Go to Step 31

18

Replace the TPS. 
Is the action complete?

—

Verify repair

—

Step

Action

Value(s)

Yes

No

4JA1-TC/4JH1-TC ENGINE DRIVEABILITY AND EMISSIONS

6E–353

19

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 20

20

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 21

21

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

—

Go to Step 22

Go to Step 23

22

Replace the CKP sensor. 
Is the action complete?

—

Verify repair

—

23

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

“Run”. 

2. Monitor the following parameters in the data

display. 

• “Desired Injection Quantity” & “Injection Quantity” 

• “Desired Injection Start” &  “Actual Injection Start” 
Are the large gap or unstable parameter displayed
between “Desired” and “Actual”?

—

Go to Step 27

Go to Step 24

24

Using the vacuum pump and check the EGR valve (if
equipped) operation for the following condition through
the small window. 

• Restrict shaft movement. Check for objects sticking

the shaft, broken diaphragm or excessive carbon
deposit. 

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

—

Verify repair

Go to Step 25

Step

Action

Value(s)

Yes

No

                  When idling or part-throttle                                            When accelerated

                                                                                     

                                                                                   

High

Desired

Low

Time

  Actual

High

Low

Desired

  Actual

Time

Vacuum Pump

Small Window

6E–354

4JA1-TC/4JH1-TC ENGINE DRIVEABILITY AND EMISSIONS

25

Using the vacuum pump and check the exhaust
throttle valve (if equipped) operation for the following
condition. 

• Restrict shaft movement. Check for objects sticking

the shaft, broken diaphragm or excessive carbon
deposit. 

Was a problem found? 

—

Verify repair

Go to Step 26

26

Check the exhaust system for a possible restriction. 

• Damaged or collapsed pipes or catalytic converter. 

• Internal muffler failure. 
If a problem is found, repair as necessary. 
Was a problem found?

—

Verify repair

Go to Step 27

27

Visually/physically inspect for the following conditions. 

• Restrict fuel supply system. Check for a pinched

fuel hose/pipe. 

• Check for a condition that causes fuel waxing or

icing, such as the customer is using an incorrect
fuel type in winter season or water mixed with the
fuel. 

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

—

Verify repair

Go to Step 28

28

Replace the fuel filter. 
Was the problem solved?

—

Verify repair

Go to Step 29

Step

Action

Value(s)

Yes

No

 

 

 

 

 

 

 

Content   ..  87  88  89  90   ..