Detonation - Pings, Spark Knock

Symptom: A mild to severe ping, usually worse under load or acceleration. Sounds like something is rattling or knocking in the engine.

POSSIBLE CAUSE ACTION


Ignition timing advanced ^ Check base timing.
SEE IGNITION SYSTEM/ ADJUSTMENT PROCEDURES.


Spark timing not retarding ^ Check with timing light.


Lean Air-Fuel mixture ^ Check fuel pressure.

^ Check Air-Fuel ratio.

^ Check O2 sensor output.

^ Perform injector balance test (SFI only only).


EGR malfunction ^ Check EGR system.
Exhaust Gas Recirculation


Poor or contaminated fuel ^ Recommend higher grade fuel