Mitsubishi Space Star. Manual - part 65

MPI  – 

Troubleshooting

13B-47

INSPECTION PROCEDURE 9

Idling speed is high. (Improper idling speed)

Probable cause

In such cases as the above, the cause is probably that the intake air volume during
idling is too great.



Malfunction of the ISC system



Malfunction of the throttle body

MUT-

II

 Self-Diag code

Are diagnosis codes displayed?

Yes

Refer to P.13B-9, INSPECTION CHART FOR DIAGNOSIS
CODES.

No

Check the ISC servo for operation sound. (Refer to P.13B-75*.)

NG

Check the ISC system. (Refer to P.13B-36, INSPECTION PROCE-
DURE FOR DIAGNOSIS CODE P0505.)

OK

MUT-

II

 Data list

14 Throttle position sensor (Refer to P.13B-65.)

NG

Check the throttle position sensor system. 
(Refer to P.13B-16, INSPECTION PROCEDURE FOR DIAGNO-
SIS CODE P0120.)

OK

MUT-

II

 Data list

21 Engine coolant temperature sensor (Refer to P.13B-65.)

NG

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

OK

MUT-

II

 Data list

28 A/C switch (Refer to P.13B-65.)

NG

Check the A/C switch and A/C relay system. 
(Refer to P.13B-62, INSPECTION PROCEDURE 29.)

OK

Basic idle adjustment (Refer to P.13B-66*.)

Check trouble symptom.

NG

Clean the throttle valve area. (Refer to P.13B-65*.)

NOTE:
*:

Refer to the ’99 SPACE STAR Workshop Manual (Pub. No. CMXE99E1)

INSPECTION PROCEDURE 10

Idling speed is low. (Improper idling speed)

Probable cause

In cases such as the above, the cause is probably that the intake air volume during
idling is too small.



Malfunction of the ISC system



Malfunction of the throttle body

MUT-

II

 Self-Diag code

Are diagnosis codes displayed?

Yes

Refer to P.13B-9, INSPECTION CHART FOR DIAGNOSIS
CODES.

No

Check the ISC servo for operation sound. (Refer to P.13B-75*.)

NG

Check the ISC system. (Refer to P.13B-36, INSPECTION PROCE-
DURE FOR DIAGNOSIS CODE P0505.)

OK

MUT-

II

 Data list

14 Throttle position sensor (Refer to P.13B-65.)

NG

Check the throttle position sensor system. (Refer to P.13B-16,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE P0120.)

OK

MUT-

II

 Data list

21 Engine coolant temperature sensor (Refer to P.13B-65.)

NG

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

OK

Basic idle adjustment (Refer to P.13B-66*.)

Check trouble symptom.

NG

Clean the throttle valve area. (Refer to P.13B-65*.)

NOTE:
*:

Refer to the ’99 SPACE STAR Workshop Manual (Pub. No. CMXE99E1)

MPI  – 

Troubleshooting

13B-48

INSPECTION PROCEDURE 11

When the engine is cold, it stalls at idling. (Die out)

Probable cause

In such cases as the above, the cause is probably that the air/fuel mixture is
inappropriate when the engine is cold, or that the intake air volume is insufficient.



Malfunction of the ISC system



Malfunction of the throttle body



Malfunction of the injector system



Malfunction of the ignition system

Were the battery terminals disconnected?

Yes

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

No

MUT-

II

 Self-Diag code

Are diagnosis codes displayed?

Yes

Refer to P.13B-9, INSPECTION CHART FOR DIAGNOSIS
CODES.

No

Does the engine stall right after the accelerator pedal is released?

Yes

Clean the throttle valve area. (Refer to P.13B-65*.)

No

Is engine-idling stable after the warming-up?

No

Check if the unstable idling (Rough idling, hunting). 
(Refer to P.13B-45, INSPECTION PROCEDURE 8.)

Yes

Check the ISC servo for operation sound. (Refer to P.13B-75*.)

NG

Check the ISC system. (Refer to P.13B-36, INSPECTION PROCE-
DURE FOR DIAGNOSIS CODE P0505.)

OK

Check the injector for operation sound.

NG

Check the injector system. (Refer to P.13B-26, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE P0201, P0202, P0203,
P0204.)

OK

MUT-

II

 Data list

14 Throttle position sensor (Refer to P.13B-65.)

NG

Check the throttle position sensor system. (Refer to P.13B-16,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE P0120.)

OK

MUT-

II

 Data list

21 Engine coolant temperature sensor (Refer to P.13B-65.)

NG

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

OK

Check the fuel pressure. (Refer to P.13B-67*.)

OK

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

NG

Check that the distributor is installed properly.

OK

Check the following items.



Check the ignition coil, spark plugs, spark plug cables. (Refer to GROUP 16 – On-vehicle Service.)



Check the compression pressure. (Refer to GROUP 11B – On-vehicle Service.)



Check the engine oil viscosity.

OK

MUT-

II

 Actuator test

10 EGR control solenoid valve (Refer to P.13B-70.)

NG

Check the EGR control solenoid valve system. (Refer to P.13B-32,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE P0403.)

NOTE:
*:

Refer to the ’99 SPACE STAR Workshop Manual (Pub. No. CMXE99E1)

MPI  – 

Troubleshooting

13B-49

INSPECTION PROCEDURE 12

When the engine is hot, it stalls at idling. (Die out)

Probable cause

In such cases as the above, the cause is probably that ignition system, air/fuel
mixture, idle speed control (ISC) or compression pressure is defective.
In addition, if the engine suddenly stalls, the cause may also be a defective connector
contact.



Malfunction of the ignition system



Malfunction of air-fuel ratio control system



Malfunction of the ISC system



Drawing air into intake system



Improper connector contact

Were the battery terminals disconnected?

Yes

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

No

MUT-

II

 Self-Diag code

Are diagnosis codes displayed?

Yes

Refer to P.13B-9, INSPECTION CHART FOR DIAGNOSIS
CODES.

No

Check the ISC servo for operation sound. (Refer to P.13B-75*.)

NG

Check the ISC system. (Refer to P.13B-36, INSPECTION PROCE-
DURE FOR DIAGNOSIS CODE P0505.)

OK

Check the injector for operation sound.

NG

Check the injector system. (Refer to P.13B-26, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE P0201, P0202, P0203,
P0204.)

OK

Does the engine stall right after the accelerator pedal is released?

Yes

Clean the throttle valve area. (Refer to P.13B-65*.)

No

Does the engine stall easily again?

No

While carrying out an intermittent malfunction simulation test (Refer
to GROUP 00 – Points to Note for Intermittent Malfunctions.),
check for sudden changes in the signals shown below.



Crank angle sensor signal



Injector drive signal



Primary and secondary
ignition signal



Fuel pump drive signal



Engine ECU power supply
voltage

Yes

MUT-

II

 Data list

14 Throttle position sensor (Refer to P.13B-65.)

NG

Check the throttle position sensor system. (Refer to P.13B-16,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE P0120.)

OK

MUT-

II

 Data list

13 Intake air temperature sensor (Refer to P.13B-65.)

NG

Check the intake air temperature sensor system. 
(Refer to P.13B-12, INSPECTION PROCEDURE FOR DIAGNO-
SIS CODE P0110.)

OK

MUT-

II

 Data list

21 Engine coolant temperature sensor (Refer to P.13B-65.)

NG

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

OK

MUT-

II

 Actuator test

10 EGR control solenoid valve (Refer to P.13B-70.)

NG

Check the EGR control solenoid valve system. (Refer to P.13B-32,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE P0403.)

OK

MUT-

II

 Data list

59 Oxygen sensor (rear)



Transmission: 2nd gear



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

NG

Check the oxygen sensor (rear) system. (Refer to P.13B-22, IN-
SPECTION PROCEDURE FOR DIAGNOSIS CODE P0136.)

OK

MUT-

II

 Data list

11 Oxygen sensor (front)

OK: 600  – 1,000 mV during sudden racing

NG

Check the oxygen sensor (front) system. (Refer to P.13B-19, IN-
SPECTION PROCEDURE FOR DIAGNOSIS CODE P0130.)

OK

To next page

MPI  – 

Troubleshooting

13B-50

OK

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

NG

Check that the distributor is installed properly.

OK

Check the following items.



Check the ignition coil, spark plugs, spark plug cables. (Refer to GROUP 16 – On-vehicle Service.)



Check if the injectors are clogged.



Check the compression pressure. (Refer to GROUP 11B – On-vehicle Service.)



Check if foreign materials (water, alcohol, etc.) got into fuel.

OK

MUT-

II

 Data list

28 A/C switch (Refer to P.13B-65.)

NG

Check the A/C switch and A/C relay system. 
(Refer to P.13B-62, INSPECTION PROCEDURE 29.)

OK

MUT-

II

 Data list

33 Electrical load switch (Refer to P.13B-65.)

NG

Check the electrical load switch system. 
(Refer to P.13B-62, INSPECTION PROCEDURE 30.)

OK

MUT-

II

 Data list

45 ISC servo position (Refer to P.13B-65.)

NG

Adjust the basic idle speed. (Refer to P.13B-66*.)

From previous page

OK

MUT-

II

 Data list

11 Oxygen sensor (front)

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

during idling

NG

Check the fuel pressure.
(Refer to P.13B-67*.)

OK

1. Inspect the intake of

air into the air intake
system.



Broken intake man-
ifold gasket



Broken vacuum hose



PCV valve does not
operate.



Broken air intake
hose

2. Check the injector for

clog.

OK

MUT-

II

 Data list

27 Power steering fluid pressure switch (Refer to P.13B-65.)

NG

Check the power steering
fluid pressure switch sys-
tem. (Refer to P.13B-61,
INSPECTION PROCE-
DURE 28.)

NOTE:
*:

Refer to the ’99 SPACE STAR Workshop Manual (Pub. No. CMXE99E1)