GM Service Manual Online
For 1990-2009 cars only

Checks

Action

DEFINITION: The fuel ignites in the intake manifold, or in the exhaust system, making a loud popping noise.

Preliminary Check

    • Refer to Symptoms - Engine Controls .

Ignition System Checks

    • Check for adequate ignition coil voltage with a J 26792 spark tester or equivalent. Refer to Electronic Ignition (EI) System Diagnosis .
    • Check the spark plugs for correct operation and performance. Refer to Spark Plug Inspection .
    • Check for the correct ignition timing. Refer to Ignition System Timing Adjustment .

Engine Mechanical Checks

    • Check for any of the following engine mechanical problems:
       - An incorrect valve lash
       - Any broken or weak valve springs
       - A low compression
       - Any sticking or leaking valves
       - An incorrect valve timing
       - An incorrect or worn camshaft
    • Refer to Engine Compression Test in Engine Mechanical - 2.0L.
    • Check the intake and exhaust system for casting flash or other restrictions.

Additional Checks

    • Check for the proper fuel pressure. Refer to Fuel System Diagnosis .
    • Verify the PCM grounds are clean, tight, and in the proper locations. Refer to Engine Controls Schematics Power and Ground.
    • Check the Service Bulletins for any updates or information.