Mitsubishi MOTORS Space Runner 1999 Workshop Manual Supplement page 515

13B-34
INSPECTION PROCEDURE 15
Hesitation, sag or stumble
In cases such as the above, the cause is probably that ignition system, air/fuel
mixture or compression pressure is defective.
MUT-II Self-Diag code
Are diagnosis codes displayed?
Check the injectors for operation sound.
Check the ignition timing.
(Refer to GROUP 11A – On-vehicle Service.)
MUT-II Data list
13 Intake air temperature sensor (Refer to P.13B-48.)
MUT-II Data list
21 Engine coolant temperature sensor (Refer to P.13B-49.)
MUT-II Data list
14 Throttle position sensor (Refer to P.13B-48.)
MUT-II Actuator test
10 EGR control solenoid valve (Refer to P.13B-52.)
MUT-II Data list
59 Oxygen sensor (rear) (Refer to P.13B-51.)
Transmission: 2nd gear
Driving with throttle widely open
OK: 600 – 1,000 mV
MUT-II Data list
11 Oxygen sensor (front)
OK: 600 – 1,000 mV during sudden racing
MUT-II Data list
11 Oxygen sensor (front)
OK: Changes between 0 – 400 mV and 600 – 1,000 mV
during idling
Check the fuel pressure. (Refer to P.13B-67.)
Check the following items.
Check the ignition coil, spark plugs, spark plug cables. (Refer to GROUP 16 – On-vehicle Service.)
Check the EGR control system. (Refer to GROUP 17 – Emission Control System.)
Check the compression pressure. (Refer to GROUP 11A – On-vehicle Service.)
Check the fuel filter or fuel line for clogging.
MPI –
No
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
Troubleshooting
Probable cause
Malfunction of the ignition system
Malfunction of air-fuel ratio control system
Malfunction of the fuel supply system
Malfunction of the EGR control solenoid valve system
Poor compression
Yes
Refer to P.13B-9, INSPECTION CHART FOR DIAGNOSIS
CODES.
NG
Check the injector system. (Refer to P.13B-17, INSPECTION PRO-
CEDURE FOR DIAGNOSIS CODE 41.)
NG
Check that the distributor is installed properly.
NG
Check the intake air temperature sensor system. (Refer to
P.13B-11, INSPECTION PROCEDURE FOR DIAGNOSIS CODE
13.)
NG
Check the engine coolant temperature sensor system.
(Refer to P.13B-13, INSPECTION PROCEDURE FOR DIAGNO-
SIS CODE 21.)
NG
Check the throttle position sensor system. (Refer to P.13B-12,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE 14.)
NG
Check the EGR control solenoid valve system.
(Refer to P.13B-47, INSPECTION PROCEDURE 34.)
NG
Check the oxygen sensor (rear) system. (Refer to P.13B-19, IN-
SPECTION PROCEDURE FOR DIAGNOSIS CODE 59.)
NG
Check the oxygen sensor (front) system. (Refer to P.13B-10, IN-
SPECTION PROCEDURE FOR DIAGNOSIS CODE 11.)
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
hose
2. Check the injector for
clog.
intake