Maintenance Manual for J2 Sedan
Electronic Control System
of Engine
235
Trouble phenomenon 9: Normal start-up but unstable idling speed or flameout with partially load
(for example, when the air conditioner is on)
General trouble position:
1. Air conditioning system; 2. Idle adjustor; 3.Fuel injector
General diagnosis procedure:
No.
Operating Steps
Detection
Results
Subsequent Steps
Yes
Wash related
components
1
Dismantle the idle adjustor to check whether there is carbon deposit
in the air throttle body, idle adjustor and idle bypass air passage.
No
Next step
Yes
To step 4
2
Observe whether power output of engine is increased air
conditioner operation, namely, use the electric control system
diagnosis apparatus to observe the changes of ignition advance
angle, fuel injector pulse width and intake volume.
No
Next step
Yes
Next step
3
Connect the adapter of electric control system and disconnect the
connecting wire of the pin #75 of electronic control module to
check whether there is high level signal at the wire harness end with
AC turned on.
No
Repair air
conditioning system
Yes
Next step
4
Inspect pressure of air conditioning system, electromagnetic clutch
of compressor and the compressor pump of air conditioner.
No
Repair AC system
Yes
Failure of replacement
5
Dismantle the fuel injector and check whether there is leakage,
blockage or too poor flow in the fuel injector with cleaning analyzer
special for fuel injector.
No
Next step
Yes
Diagnosis help
6
Turn on the ignition switch and check whether the power supply
and earthing are normal.
No
Repair related circuit
