Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 183

6E–336

4JH1 ENGINE DRIVEABILITY AND EMISSIONS

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 30

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 30

18

Replace the TPS. 
Is the action complete?

—

Verify repair

—

Step

Action

Value(s)

Yes

No

4JH1 ENGINE DRIVEABILITY AND EMISSIONS

6E–337

19

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 23

Go to Step 20

20

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 21

21

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 22

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–338

4JH1 ENGINE DRIVEABILITY AND EMISSIONS

22

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 23

23

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 24

24

Replace the fuel filter. 
Was the problem solved?

—

Verify repair

Go to Step 25

25

Remove the eye bolt with gauze filter from the
injection pump and check for the following conditions. 

• Objects blocking at the gauze filter. Check for a

condition that causes contaminated fuel, such as
the customer is using an aftermarket fuel filter or
extended maintenance interval. 

• 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 the problem found?

—

Replace the eye 

bolt with gauze 

filter and verify 

repair

Go to Step 26

26

Remove the injection nozzles from the engine and
check for the following conditions. 

• Improper splay condition. 

• Operating pressure is incorrect. 
If a problem is found, repair as necessary. 
Was the problem found?

—

Replace the 

injection nozzle 

and verify repair

Go to Step 27

Step

Action

Value(s)

Yes

No

1

st

 Stage

2

nd

 Stage

20.0 - 21.0 Mpa

(204 - 214 kg/cm

2

)

34.3 - 35.8 Mpa

(350 - 365 kg/cm

2

)

4JH1 ENGINE DRIVEABILITY AND EMISSIONS

6E–339

27

Check the engine compression pressure for each
cylinders. 
If a problem is found, repair as necessary. 
Was the problem found?

More than 30 

Mpa (31.0 kg/

cm

2

)

Verify repair

Go to Step 28

28

Check the inlet/exhaust valve clearance for each
valves. 
Are the valve clearances within the specified value?

0.4mm at cold 

(In/Ex)

Go to Step 29

Adjust and 

verify repair

29

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 

• All electrical connections within a suspected circuit

and/or system 

Was a problem found?

—

Verify repair

Go to Step 30

30

Is the ECM programmed with the latest software
release? 
If not, download the latest software to the ECM using
the “SPS (Service Programming System)”. 
Was the problem solved?

—

Verify repair

Go to Step 31

31

Substitute a known good ECM and recheck. 
Was the problem solved? 
IMPORTANT: The replacement ECM must be
programmed. Refer to section of the Service
Programming System (SPS) in this manual. 
Following ECM programming, the immobiliser system
(if equipped) must be linked to the ECM. Refer to
section 11 “Immobiliser System-ECM replacement” for
the ECM/Immobiliser linking procedure. 

—

Go to Step 32

Go to Step 33

Step

Action

Value(s)

Yes

No