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
SEE COMPUTERS AND CONTROL SYSTEMS Computers and Control Systems

Poor or contaminated fuel Check for excessive alcohol content

Recommend higher grade fuel

Incorrect fuel pressure Proceed to FUEL PUMP

Vacuum leak Inspect vacuum hoses for
proper routing and damaged lines

Check intake manifold and
throttle chamber base