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
Recommend higher grade fuel



Incorrect fuel pressure ^ Check fuel pump pressure.



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

NOTE: To determine if the condition is caused by a rich or lean system, the vehicle should be driven at the speed of the complaint. Monitoring block learn will help identify problem.
Lean - Block learn near 198
Rich - Block learn near 58