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
Poor or contaminated fuel Check for excessive alcohol content. Alcohol In Fuel Test
Recommend higher grade fuel
Incorrect fuel pressure Test fuel pressure.
Vacuum leak Inspect vacuum hoses for
proper routing and damaged lines
Check intake manifold and
throttle chamber base