Detonation/Spark-Knock/Pings

Definition: A mild to severe ping, usually worse under acceleration. The engine makes sharp metallic knocks that change with throttle opening.
POSSIBLE CAUSE ACTION
Lean operating condition Check computer controls, refer to COMPUTERIZED ENGINE CONTROLS


Poor or contaminated fuel Check for excessive alcohol content, refer to ALCOHOL IN FUEL TEST
Recommend higher grade fuel

Incorrect fuel pressure Refer to FUEL SYSTEM DIAGNOSIS

Vacuum leak Inspect vacuum hoses for proper routing and damaged lines
Check intake manifold throttle body etc.