Mitsubishi MOTORS Space Runner 1998, Workshop Manual

Page: 166 / 1164

GDI <4G6> -
Troubleshooting
13A-48
INSPECTION PROCEDURE 7
Unstable idling (rough idle, hunting) Probable cause
This malfunction is probably caused by a faulty ignition system, improper air/fuel ratio,
a faulty electronic-controlled throttle valve system, improper compression pressure,
etc. As many causes can be suspected, diagnose from easier items.
D Malfunction of the ignition system
D Malfunction of the air/fuel ratio control system
D Malfunction of the electronic-control throttle valve
system
D Improper compression pressure
D Air sucking into the air intake system
Has the battery been disconnected recently?
Yes
Warm up the engine, and then let it run at idle for approx. ten
minutes.
No
MUT-
II
Self-Diag code
Is a diagnosis code displayed?
Yes
Refer to P.13A-13, INSPECTION CHART FOR DIAGNOSIS
CODES.
No
Does the engine idle speed fluctuates excessively (excessive hunt-
ing)?
Yes
Clean around the throttle valve. (Refer to P.13A-97.)
No
MUT-
II
Data list
14 Throttle position sensor (2nd channel) (Refer to P.13A-76.)
NG
Check the throttle position sensor (2nd channel) system. (Refer
to P.13A-17, INSPECTION PROCEDURE FOR DIAGNOSIS
CODE 14.)
OK
MUT-
II
Data list
79 Throttle position sensor (1st channel) (Refer to P.13A-80.)
NG
Check the throttle valve position feedback system. (Refer to
P.13A-37, INSPECTION PROCEDURE FOR DIAGNOSIS CODE
92.)
OK
MUT- II Data list
26 Accelerator pedal position switch (Refer to P.13A-77.)
NG
Check the accelerator pedal position switch system. (Refer to
P.13A-67, INSPECTION PROCEDURE 27.)
OK
MUT-
II
Data list
13 Intake air temperature sensor (Refer to P.13A-75.)
NG
Check the intake air temperature sensor system. (Refer to P.13A-16,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE 13.)
OK
MUT- II Data list
25 Barometric pressure sensor (Refer to P.13A-77.)
NG
Check the barometric pressure sensor system. (Refer to P.13A-22,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE 25.)
OK
MUT-
II
Data list
21 Engine coolant temperature sensor (Refer to P.13A-76.)
NG
Check the engine coolant temperature sensor. (Refer to P.13A-18,
INSPECTION PROCEDURE FOR DIAGNOSIS CODE 21.)
OK
MUT- II Actuator test
08 Purge control solenoid valve (Refer to P.13A-81.)
NG
Check the purge control solenoid valve system. (Refer to P.13A-70,
INSPECTION PROCEDURE 30.)
OK
MUT-
II
Data list
11 Oxygen sensor (front)
OK:
600 - 1,000 mV when the engine is suddenly raced
NG
Check the oxygen sensor (front) system. (Refer to P.13A-14, IN-
SPECTION PROCEDURE FOR DIAGNOSIS CODE 11.)
OK
MUT-
II
Data list
59 Oxygen sensor (rear) (Refer to P.13A-79.)
D Transmission: 2nd gear <M/T>, L range <A/T>
D Driving with throttle widely open
OK:
600 - 1,000 mV
NG
Check the oxygen sensor (rear) system. (Refer to P.13A-30, IN-
SPECTION PROCEDURE FOR DIAGNOSIS CODE 59.)
OK
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