Mitsubishi Pajero Pinin. Manual - part 118

MPI <4G9> – 

Troubleshooting

13C-58

INSPECTION PROCEDURE 13

The engine stalls when starting the car. (Pass out)

Probable cause

In cases such as the above, the cause is probably misfiring due to a weak spark,
or an inappropriate air/fuel mixture when the accelerator pedal is depressed.

D

Drawing air into intake system

D

Malfunction of the ignition system

OK

Check the following items.

D

Check the ignition coil, spark plugs, spark plug cables.

D

Check if air was drawn into the intake system.

Broken intake manifold gasket
Broken or disconnected vacuum hose
Improper operation of the PCV valve
Broken air intake hose

NG

Check the EGR control solenoid valve system. (Refer to P.13C-36,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE P0403.)

No

MUT-

II

 Actuator test

10 EGR control solenoid valve (Refer to P.13C-79.)

MUT-

II

 Self-Diag code

Are diagnosis codes displayed?

Yes

Refer to P.13C-12, INSPECTION CHART FOR DIAGNOSIS
CODES.

INSPECTION PROCEDURE 14

The engine stalls when decelerating.

Probable cause

In cases such as the above, the cause is probably that the intake air volume is
insufficient due to a defective idle speed control (ISC) servo system.

D

Malfunction of the ISC system

OK

Check the following items.

D

Check the ignition coil, spark plugs, spark plug cables.

D

Clean the throttle valve area.

NG

Check the EGR control solenoid valve system. (Refer to P.13C-36,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE P0403.)

No

MUT-

II

 Actuator test

10 EGR control solenoid valve (Refer to P.13C-79.)

Yes

Check the vehicle speed sensor system. (Refer to P.13C-40, IN-
SPECTION PROCEDURE FOR DIAGNOSIS CODE P0500.)

OK

MUT-

II

 Data list

45 ISC servo position

D

Is the idle speed control (ISC) servo position drops to 0 –
2 steps when decelerating (engine r/min less than 1,000)?

NG

Check the throttle position sensor system. (Refer to P.13C-22,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE P0120.)

OK

MUT-

II

 Data list

14 Throttle position sensor (Refer to P.13C-75.)

Yes

Refer to P.13C-12, INSPECTION CHART FOR DIAGNOSIS
CODES.

No

MUT-

II

 Self-Diag code

Are diagnosis codes displayed?

Were the battery terminals disconnected?

Yes

After warming-up, let the engine run at idling for 10 minutes.

MPI <4G9> – 

Troubleshooting

13C-59

INSPECTION PROCEDURE 15

Hesitation, sag or stumble

Probable cause

In cases such as the above, the cause is probably that ignition system, air/fuel
mixture or compression pressure is defective.

D

Malfunction of the ignition system

D

Malfunction of air-fuel ratio control system

D

Malfunction of the fuel supply system

D

Malfunction of the EGR control solenoid valve system

D

Poor compression

NG

Check the throttle position sensor system. (Refer to P.13C-22,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE P0120.)

To the next page

NG

Check the oxygen sensor (front) system. (Refer to P.13C-25, IN-
SPECTION PROCEDURE FOR DIAGNOSIS CODE P0130.)

OK

MUT-

II

 Data list

11 Oxygen sensor

OK: Changes between 600 – 1,000 mV during sudden racing

NG

Check the oxygen sensor (rear) system. (Refer to P.13C-27, IN-
SPECTION PROCEDURE FOR DIAGNOSIS CODE P0136.)

OK

MUT-

II

 Data list

59 Oxygen sensor (rear)

D

Transmission: 2nd gear <M/T>, L range <A/T>

D

Driving with throttle widely open
OK: 600 – 1,000 mV

NG

Check the EGR control solenoid valve system. 
(Refer to P.13C-36, INSPECTION PROCEDURE FOR DIAGNO-
SIS CODE P0403.)

OK

MUT-

II

 Actuator test

10 EGR control solenoid valve (Refer to P.13C-79.)

OK

MUT-

II

 Data list

14 Throttle position sensor (Refer to P.13C-75.)

NG

Check the engine coolant temperature sensor system. 
(Refer to P.13C-20, INSPECTION PROCEDURE FOR DIAGNO-
SIS CODE P0115.)

OK

MUT-

II

 Data list

21 Engine coolant temperature sensor (Refer to P.13C-75.)

NG

Check the barometric pressure sensor system. (Refer to P.13C-16,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE P0105.)

OK

MUT-

II

 Data list

25 Barometric pressure sensor (Refer to P.13C-76.)

NG

Check the intake air temperature sensor system. (Refer to
P.13C-18, INSPECTION PROCEDURE FOR DIAGNOSIS CODE
P0110.)

OK

MUT-

II

 Data list

13 Intake air temperature sensor (Refer to P.13C-75.)

NG

Check that the crank angle sensor is installed properly.

OK

Check the ignition timing. 
(Refer to GROUP 11B – On-vehicle Service.)

NG

Check the injector system. (Refer to P.13C-30, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE P0201, P0202, P0203, P0204.)

No

Check the injectors for operation sound.

MUT-

II

 Self-Diag code

Are diagnosis codes displayed?

Yes

Refer to P.13C-12, INSPECTION CHART FOR DIAGNOSIS
CODES.

OK

MPI <4G9> – 

Troubleshooting

13C-60

OK

Check the following items.

D

Check the ignition coil, spark plugs, spark plug cables.

D

Check the EGR control system.

D

Check the compression pressure.

D

Check the fuel filter or fuel line for clogging.

OK

Check the fuel pressure. (Refer to P.13A-78.)

OK

1. Inspect the intake of

air into the air intake
system

D

Broken intake 
manifold gasket

D

Broken vacuum 
hose

D

PCV valve does
not operate.

D

Broken air intake
hose

2. Check the injector for

clog.

NG

Check the fuel pressure.
(Refer to P.13C-98.)

OK

MUT-

II

 Data list

11 Oxygen sensor

OK: Changes between 0 – 400 mV and 600 – 1,000 mV

during idling

From the previous page

INSPECTION PROCEDURE 16

The feeling of impact or vibration when accelerating

Probable cause

In cases such as the above, the cause is probably that there is an ignition leak
accompanying the increase in the spark plug demand voltage during acceleration.

D

Malfunction of the ignition system

No

Check the following items.

D

Check the ignition coil, spark plugs, spark plug cables.

D

Check for occurrence of ignition leak.

MUT-

II

 Self-Diag code

Are diagnosis codes displayed?

Yes

Refer to P.13C-12, INSPECTION CHART FOR DIAGNOSIS
CODES.

INSPECTION PROCEDURE 17

The feeling of impact or vibration when decelerating.

Probable cause

Malfunction of the ISC system is suspected.

D

Malfunction of the ISC system

OK

Clean the throttle valve area. (Refer to P.13C-96.)

NG

Check the throttle position sensor system. (Refer to P.13C-22,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE P0120.)

OK

MUT-

II

 Data list

14 Throttle position sensor (Refer to P.13C-75.)

NG

Check the ISC system. (Refer to P.13C-40, INSPECTION PROCE-
DURE FOR DIAGNOSIS CODE P0505.)

No

Check the ISC servo for operation sound. (Refer to P.13C-107.)

MUT-

II

 Self-Diag code

Are diagnosis codes displayed?

Yes

Refer to P.13C-12, INSPECTION CHART FOR DIAGNOSIS
CODES.

MPI <4G9> – 

Troubleshooting

13C-61

INSPECTION PROCEDURE 18

Poor acceleration

Probable cause

Defective ignition system, abnormal air-fuel ratio, poor compression pressure, etc.
are suspected.

D

Malfunction of the ignition system

D

Malfunction of air-fuel ratio control system

D

Malfunction of the fuel supply system

D

Poor compression pressure

D

Clogged exhaust system

To the next page

NG

Check the oxygen sensor (front) system. (Refer to P.13C-25, IN-
SPECTION PROCEDURE FOR DIAGNOSIS CODE P0130.)

OK

MUT-

II

 Data list

11 Oxygen sensor

OK: Changes between 600–1,000 mV during sudden racing

NG

Check the oxygen sensor (rear) system. (Refer to P.13C-27, IN-
SPECTION PROCEDURE FOR DIAGNOSIS CODE P0136.)

OK

MUT-

II

 Data list

59 Oxygen sensor (rear)

D

Transmission: 2nd gear <M/T>, L range <A/T>

D

Driving with throttle widely open
OK: 600 – 1,000 mV

NG

Check the EGR control solenoid valve system. 
(Refer to P.13C-36, INSPECTION PROCEDURE FOR DIAGNO-
SIS CODE P0403.)

OK

MUT-

II

 Actuator test

10 EGR control solenoid valve (Refer to P.13C-79.)

NG

Check the throttle position sensor system. (Refer to P.13C-22,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE P0120.)

OK

MUT-

II

 Data list

14 Throttle position sensor (Refer to P.13C-75.)

NG

Check the engine coolant temperature sensor system. 
(Refer to P.13C-20, INSPECTION PROCEDURE FOR DIAGNO-
SIS CODE P0115.)

OK

MUT-

II

 Data list

21 Engine coolant temperature sensor (Refer to P.13C-75.)

NG

Check the barometric pressure sensor system. (Refer to P.13C-16,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE P0105.)

OK

MUT-

II

 Data list

25 Barometric pressure sensor (Refer to P.13C-76.)

NG

Check the intake air temperature sensor system. (Refer to
P.13C-18, INSPECTION PROCEDURE FOR DIAGNOSIS CODE
P0110.)

OK

MUT-

II

 Data list

13 Intake air temperature sensor (Refer to P.13C-74.)

NG

Check that the crank angle sensor is installed properly.

OK

Check the ignition timing. 
(Refer to GROUP 11B – On-vehicle Service.)

NG

Check the injector system. (Refer to P.13C-30, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE P0201, P0202, P0203, P0204.)

No

Check the injectors for operation sound.

MUT-

II

 Self-Diag code

Are diagnosis codes displayed?

Yes

Refer to P.13C-12, INSPECTION CHART FOR DIAGNOSIS
CODES.

OK