Engine Poor Driveability
The following conditions apply to this symptom:
• Engine stalls/quits, engine runs rough, misses, buck/jerk, hesitation/stumble acceleration, surges, rolling idle.
• Engine stops unexpectedly at beginning of acceleration or during acceleration.
• Engine stops unexpectedly while cruising.
• Engine speed fluctuates during acceleration.
• Engine misses during acceleration.
• Vehicle bucks/jerks during acceleration, cruising or deceleration.
• Momentary pause during acceleration.
• Momentary minor loss in engine output.
1.
PRELIMINARY CHECKS
NOTE :
Be aware of the over RPM limiting functions of the ECM.
• Carry out the following preliminary checks:
− Fuel quality
− Vacuum lines (check for damage and correct routing)
− Intake air system (check for damaged tubes and dirty air filter)
− Vehicle wiring (disconnected, corroded/damaged)
− Throttle linkage.
− Radiator (obstructed)
− Transaxle
Are all checks OK?
Yes
>> Go to the next step.
No
>> Repair as necessary. Verify symptom no longer exists.
2.
CHECK FOR STALL AT IDLE
• Check for engine stall at idle.
NOTE :
Confirm that proper vehicle maintenance has been performed before continuing with engine diagnosis.
• Inspect the following components:
− Clean the injectors
− Fuel filter
− Intake air filter
− Throttle body
− Spark plugs
− Spark plug wires
Does the engine now stall at idle?
Yes
>> Repair as necessary.
No
>> Go to the next step.
ELECTRONIC ENGINE CONTROLS - ENGINE SYMPTOM DIAGNOSIS
03
03–193
Chery Automobile Co., Ltd.
To Next Page
