Mitsubishi Colt Ralliart. Manual - part 734

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-261

Inspection Procedure 10: Hesitation, Sag, Poor Acceleration, Stumble, Surge

COMMENT ON TROUBLE SYMPTOM

• Failure is possibly caused by failed ignition sys-

tem, improper air-fuel ratio, incorrect compres-
sion pressure, or other faults.

PROBABLE CAUSES

• Failed air-fuel ratio control system

• Failed ignition system

• Failed fuel system

• Failed intake and exhaust system

• Failed exhaust gas cleaning systems

• Failed electronically controlled throttle valve sys-

tem

• Throttle valve fouled

• Improper compression pressure

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code

Q: Is the diagnosis code output?

YES : 

Inspection chart for diagnosis code (Refer 

to 

P.13B-18

).

NO : 

Go to Step 2 .

STEP 2. Check injector for operating sound.

• Check injector for operating sound (Refer to 

P.13B-367

).

Q: Can operating sound be heard?

YES : 

Go to Step 3 .

NO : 

Check the injector system of the defective 

cylinder.

(Refer to Code No. P0201: No. 1 Injector 

System 

P.13B-92

).

(Refer to Code No. P0202: No. 2 Injector 

System 

P.13B-97

).

(Refer to Code No. P0203: No. 3 Injector 

System 

P.13B-102

).

(Refer to Code No. P0204: No. 4 Injector 

System 

P.13B-107

).

STEP 3. M.U.T.-III data list

• Refer to Data List Reference Table 

P.13B-335

.

a. Item 13: Intake air temperature sensor
b. Item 14: Throttle position sensor (sub)

c. Item 21: Engine coolant temperature sensor

d. Item 77: Accelerator pedal position sensor 

(sub)

e. Item 78: Accelerator pedal position sensor 

(main)

f. Item 79: Throttle position sensor (main)

Q: Are the check results normal?

YES : 

Go to Step 4 .

NO : 

Perform the diagnosis code classified check 
procedure for the sensor that has shown an 
abnormal data value (Refer to Inspection 
Chart for Diagnosis Code 

P.13B-18

).

STEP 4. Check purge control solenoid valve 
itself.

• Check purge control solenoid valve itself (Refer 

to GROUP 17 

− Emission Control System − 

Evaporative Emission Control System 

− Purge 

Control Solenoid Valve Check 

P.17-16

).

Q: Is the check result normal?

YES : 

Go to Step 5 .

NO : 

Replace purge control solenoid valve.

STEP 5. M.U.T.-III data list

• Refer to Data List Reference Table 

P.13B-335

.

a. Item 11: Oxygen sensor (front)
b. Item 59: Oxygen sensor (rear)

Q: Is the check result normal?

YES : 

Go to Step 6 .

NO : 

Perform the diagnosis code classified check 
procedure for the sensor that has shown an 
abnormal data value (Refer to Inspection 
Chart for Diagnosis Code 

P.13B-18

).

STEP 6. Visual check of ignition spark.

• Remove the spark plug and install it to the ignition 

coil.

• Connect the ignition coil connector.

• Remove all injector connector.

• At the engine start, check each spark plug pro-

duces a spark.

Q: Is the check result normal?

YES : 

Go to Step 8 .

NO : 

Go to Step 7 .

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Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-262

STEP 7. Check spark plug.

• Check spark plug (Refer to GROUP 16 − Ignition 

System 

− On-vehicle Service 

P.16-35

).

Q: Is the check result normal?

YES : 

Check ignition circuit system (Refer to 

Inspection Procedure 26 

P.13B-327

).

NO : 

Replace spark plug.

STEP 8. Check throttle body (throttle valve) for 
contamination.

Q: Is the check result normal?

YES : 

Go to Step 9 .

NO : 

Clean throttle body (throttle valve) (Refer to 

P.13B-358

).

STEP 9. M.U.T.-III actuator test

• Item 12: Waste gate solenoid valve

OK: When actuated, operating sound can be 
heard.

Q: Is the check result normal?

YES : 

Go to Step 10 .

NO : 

Check waste gate solenoid valve system 
(Refer to Code No. P0243 

P.13B-119

).

STEP 10. Check turbocharger boost pressure.

• Check turbocharger boost pressure (Refer to 

GROUP 15 

− On-vehicle Service − Supercharg-

ing Pressure Control System 

P.15-3

).

Q: Is the check result normal?

YES : 

Go to Step 11 .

NO : 

Repair.

STEP 11. Check boost pressure control system.

• Check boost pressure control system (Refer to 

GROUP 15 

− On-vehicle Service − Supercharg-

ing Pressure Control System 

P.15-3

).

Q: Is the check result normal?

YES : 

Go to Step 12 .

NO : 

Repair.

STEP 12. M.U.T.-III actuator test

• Item 09: Fuel pressure solenoid valve

OK: When actuated, operating sound can be 
heard.

Q: Is the check result normal?

YES : 

Go to Step 13 .

NO : 

Check fuel pressure solenoid valve system 
(Refer to Code No. P0090 

P.13B-25

).

STEP 13. Check compression pressure.

• Check compression pressure (Refer to GROUP 

11C 

− On-vehicle Service − Compression Pres-

sure Check 

P.11C-13

).

Q: Is the check result normal?

YES : 

Go to Step 14 .

NO : 

Repair.

STEP 14. Fuel pressure measurement.

• Fuel pressure measurement (Refer to Fuel Pres-

sure Test 

P.13B-358

).

Q: Is the check result normal?

YES : 

Replace engine-ECU.

NO : 

Repair.

Inspection Procedure 11: The Feeling of Impact or Vibration when Accelerating

COMMENT ON TROUBLE SYMPTOM

• Failure is possibly caused by ignition leak with 

rise in spark plug-required voltage at accelera-
tion, failed electronically controlled throttle valve 
system, or other faults.

PROBABLE CAUSES

• Failed ignition system

• Failed electronically controlled throttle valve sys-

tem

• Throttle valve fouled

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code

Q: Is the diagnosis code output?

YES : 

Inspection chart for diagnosis code (Refer 

to 

P.13B-18

).

NO : 

Go to Step 2 .

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-263

STEP 2. M.U.T.-III data list

• Refer to Data List Reference Table 

P.13B-335

.

a. Item 14: Throttle position sensor (sub)
b. Item 77: Accelerator pedal position sensor 

(sub)

c. Item 78: Accelerator pedal position sensor 

(main)

d. Item 79: Throttle position sensor (main)

Q: Are the check results normal?

YES : 

Go to Step 3 .

NO : 

Perform the diagnosis code classified check 
procedure for the sensor that has shown an 
abnormal data value (Refer to Inspection 
Chart for Diagnosis Code 

P.13B-18

).

STEP 3. Check throttle body (throttle valve) for 
contamination.

Q: Is the check result normal?

YES : 

Go to Step 4 .

NO : 

Clean throttle body (throttle valve) (Refer to 

P.13B-358

).

STEP 4. Visual check of ignition spark.

• Remove the spark plug and install it to the ignition 

coil.

• Connect the ignition coil connector.

• Remove all injector connector.

• At the engine start, check each spark plug pro-

duces a spark.

Q: Is the check result normal?

YES : 

Replace engine-ECU.

NO : 

Go to Step 5 .

STEP 5. Check spark plug.

• Check spark plug (Refer to GROUP 16 − Ignition 

System 

− On-vehicle Service 

P.16-35

).

Q: Is the check result normal?

YES : 

Check ignition circuit system (Refer to 

Inspection Procedure 26 

P.13B-327

).

NO : 

Replace spark plug.

Inspection Procedure 12: The Feeling of Impact or Vibration when Decelerating

COMMENT ON TROUBLE SYMPTOM

• Failure is possibly caused by insufficient air 

intake due to failed electronically controlled throt-
tle valve system.

PROBABLE CAUSES

• Failed electronically controlled throttle valve sys-

tem

• Throttle valve fouled

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code

Q: Is the diagnosis code output?

YES : 

Inspection chart for diagnosis code (Refer 

to 

P.13B-18

).

NO : 

Go to Step 2 .

STEP 2. M.U.T.-III data list

• Refer to Data List Reference Table 

P.13B-335

.

a. Item 14: Throttle position sensor (sub)
b. Item 77: Accelerator pedal position sensor 

(sub)

c. Item 78: Accelerator pedal position sensor 

(main)

d. Item 79: Throttle position sensor (main)

Q: Are the check results normal?

YES : 

Go to Step 3 .

NO : 

Perform the diagnosis code classified check 
procedure for the sensor that has shown an 
abnormal data value (Refer to Inspection 
Chart for Diagnosis Code 

P.13B-18

).

STEP 3. Check throttle body (throttle valve) for 
contamination.

Q: Is the check result normal?

YES : 

Replace engine-ECU.

NO : 

Clean throttle body (throttle valve) (Refer to 

P.13B-358

).

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-264

Inspection Procedure 13: Knocking

COMMENT ON TROUBLE SYMPTOM

• Failure is possibly caused by failed knock control 

system, improper thermal value of spark plug, or 
other faults.

PROBABLE CAUSES

• Failed detonation sensor

• Failed detonation control system

• Defective spark plug

• Failed ignition system

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code

Q: Is the diagnosis code output?

YES : 

Inspection chart for diagnosis code (Refer 

to 

P.13B-18

).

NO : 

Go to Step 2 .

STEP 2. Visual check of ignition spark.

• Remove the spark plug and install it to the ignition 

coil.

• Connect the ignition coil connector.

• Remove all injector connector.

• At the engine start, check each spark plug pro-

duces a spark.

Q: Is the check result normal?

YES : 

Check detonation sensor system (Refer to 

Code No. P0325 

P.13B-138

).

NO : 

Go to Step 3 .

STEP 3. Check spark plug.

• Check spark plug (Refer to GROUP 16 − Ignition 

System 

− On-vehicle Service 

P.16-35

).

Q: Is the check result normal?

YES : 

Check ignition circuit system (Refer to 

Inspection Procedure 26 

P.13B-327

).

NO : 

Replace spark plug.

Inspection Procedure 14: Ignition Timing Offset

COMMENT ON TROUBLE SYMPTOM

• Failure is possibly caused by failed crank angle 

sensor, failed camshaft position sensor, incor-
rectly installed timing belt, or other faults.

PROBABLE CAUSES

• Failed crank angle sensor

• Failed camshaft position sensor

• Incorrectly installed timing belt

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code

Q: Is the diagnosis code set?

YES : 

Inspection chart for diagnosis code (Refer 

to 

P.13B-18

).

NO : 

Go to Step 2 .

Main

Index

Group

TOC