Mitsubishi Eclipse 1990 Service Manual page 586

INSPECTION PROCEDURE 8
Unstable Rough
[Comment]
In cases such as the above, the cause is probably that the ignition system, air/fuel mixture, idle
air control motor or compression pressure is defective.
Because the range of possible causes is broad, inspection is narrowed down to simple items.
Were the battery terminals disconnected recently
NO
SCAN TOOL DTC
Are diagnostic trouble codes output
Does idle speed fluctuate excessively
NO
Check the idle air control motor for operation sound
control motor for operation sound
Checktheinjectorforoperation
I
Scan tool: Inspection when idle speed is unstable.
(Refer to INSPECTION PROCEDURE 40.)
Check the ignition timing.
(Refer to GROUP On-vehicle Service.)
Check the ignition timing.
(Refer to GROUP On-vehicle
OK
SCAN TOOL Actuator test
10 EGR solenoid (Refer to
OK
Check the following items.
Check the ignition coil, spark plugs, spark plug cables.
Check the purge control System.
Check the compression pressure.
Check if foreign materials (water, alcohol, etc.) got into fuel.
Check the EGR system.
E N G I N E
AND ENGINE>
YES
NG
engine>. (Refer
Engine (Turbo)>
Engine>
NG
TSB Revision
( T U R B O )
Probable cause
Malfunction of the ignition
M a l f u n c t i o n
Malfunction of the evaporative
purge
Poor compression
Drawing air
After warming-up, let the
Refer to INSPECTION
T R O U B L E C O D E S .
(Refer to INSPECTION
.
Check the idle control system malfunction (Refer to
INSPECTION PROCEDURE FOR DIAGNOSTIC TROUBLE
CODE
PROCEDURE FOR DIAGNOSTIC TROUBLE-CODES
Check that the crankshaft position sensor and timing belt cover are
installed properly.
.
Check the exhaust gas recirculation solenoid malfunction.
(Refer to INSPECTION PROCEDURE FOR DIAGNOSTIC
TROUBLE CODE
,
of system
s y s t e m
system-
exhaust system
for minutes.'
,
FOR DIAGNOSTIC
39.)
.