Mitsubishi Electric Lancer Evolution-VII Workshop Manual page 1200

Inspection Procedure 8
Unstable idling (Rough idling, hunting), inappropriate
idling speed (High or low idling speed), engine stalls (Die
out) during idling
Causes shown on right are suspected.
Has the battery terminal been disconnected recently?
NO
MUT-II Self-Diag code
D Is a diagnosis code output?
NO
MUT-II Data list
D No. 12: Air flow sensor
D No. 13: Intake air temperature sensor
D No. 14: Throttle position sensor
D No. 21: Engine coolant temperature sensor
D No. 25: Barometric pressure sensor
(Refer to P.13A-102.)
<Reference>
Proceed to OK if all service data values are correct.
Proceed to NG if there is even one abnormal service data value.
OK
MUT-II Data list
D No. 45: Idle speed control servo position (Refer to P.13A-105.)
OK
MUT-II Data list
D No. 27: Power steering fluid pressure switch
(Refer to P.13A-103.)
OK
Check the timing marks on the timing belt.
OK
Check the air intake from the intake hose and intake manifold.
OK
Check the throttle body (throttle valve section) for contamination.
OK
MUT-II Data list
D No. 11: Oxygen sensor (front) (Refer to P.13A-102.)
OK
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MPI -
Troubleshooting
YES
After warming up the engine, idle for approximately 10 minutes.
YES
INSPECTION CHART FOR DIAGNOSIS CODE
(Refer to P.13A-12.)
NG
Refer to inspections for diagnosis code of sensor showing abnormal
service data. (Refer to P.13A-12.)
NG
Check the Idle speed control servo (stepper motor) system. (Refer
to P.13A - 49 PROCEDURE FOR DIAGNOSIS CODE P0505)
NG
Check the Power steering fluid pressure switch system. (Refer to
P.13A-51, PROCEDURE FOR DAIGNOSIS CODE P0551)
NG
Align the timing marks on the timing belt.
NG
Repair
NG
Clean the throttle body (throttle valve section).
(Refer to P.13A-126.)
NG
Check the Code No. P0130: Oxygen sensor (front) system.
(Refer to P.13A-24.)
Probable cause
D Idle speed control system malfunction
D Air/fuel ratio control system malfunction
D Ignition system malfunction
D Fuel system malfunction
D Intake and exhaust system malfunction
D Exhaust gas purifier system malfunction
D Throttle valve malfunction
D Timing belt malfunction
D Improper compression pressure
D Engine-ECU malfunction
13A-63