GM Service Manual Online
For 1990-2009 cars only

Dieseling, Run-On Petrol

Checks

Action

DEFINITION: The engine continues to run when the ignition is turned OFF, but usually runs very roughly.

Preliminary Checks

Refer to Important Preliminary Checks in Symptoms - Engine Controls .

Fuel System Checks

    • Test for correct EVAP Purge system operation.
    • Test the fuel injectors for leakage.
    • Inspect for correct throttle blade adjustment, if applicable.
    • Perform the fuel system diagnostic procedure. Refer to Fuel System Diagnosis .

Additional Checks

If the engine continues to run smoothly when the ignition is turned OFF inspect for the following:

    • Correct ignition switch adjustment
    • A short to voltage in the LPG ECM ignition feed circuit.

Dieseling, Run-On LPG

Checks

Action

DEFINITION: The engine continues to run when the ignition is turned OFF, but usually runs very roughly.

Preliminary Checks

Refer to Important Preliminary Checks in Symptoms - Engine Controls.

Fuel System Checks

    • Test for correct EVAP Purge system operation.
    • Test the fuel injectors for leakage.
    • Inspect for correct throttle blade adjustment, if applicable.
    • Perform the fuel system diagnostic procedure. Refer to Fuel System Diagnosis.

Additional Checks

If the engine continues to run smoothly when the ignition is turned OFF inspect for the following:

    • Correct ignition switch adjustment
    • A short to voltage in the LPG ECM ignition feed circuit.