Dieseling, Run-On. GMC Truck GMC K Pickup

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2000 🢒 GMC K Pickup - 4WD (CNG) 🢒 Engine 🢒 Engine Controls - 5.0L and 5.7L 🢒 Dieseling, Run-On

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 .

Fuel System Checks

•	Check for proper EVAP Purge system operation.

•	Check the fuel injectors for leakage.

•	Check 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 check for the following:

•	Proper ignition switch adjustment

•	A short to voltage in the control modules' (AF ECU, VCM/PCM or ECM) ignition feed circuits.