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 .

Main

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. P0

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