Detonation/Spark-Knock/Pings

SYMPTOM DESCRIPTION:

A mild to severe ping, usually worse under acceleration. The engine makes sharp metallic knocks that change with throttle opening.


POSSIBLE CAUSE ACTION

Lean air/fuel mixture Check computer controls, refer to "Computers And Control Systems"



Poor or contaminated fuel Check for excessive alcohol content.

Recommend higher grade fuel



Incorrect fuel pressure Check fuel pressure.



Vacuum leak Inspect vacuum hoses for proper routing and damaged lines

Check intake manifold, throttle body, etc.