Dieseling/Run-on

SYMPTOM DESCRIPTION:
Engine continues to run after key is turned "OFF", but runs very roughly. If engine runs smoothly, check ignition switch and adjustment.



SYSTEM OR COMPONENT TO CHECK ACTION

FUEL CHECK: - INJECTOR LEAKAGE (EFI)
Hookup a fuel pressure gauge,
remove and block off return line.
Turn the ignition switch ON to build pressure
within the fuel lines and then OFF.
Fuel pressure should stabilize and
remain constant.
- MPFI Systems
Energize each injector individually and note rate
of pressure drop. The drop rate should be
balanced across all injectors.
- TBI Systems
A visual check of the injector(s)
should NOT show signs of leakage.
- FEEDBACK CARBURETORS
Defective Idle Solenoid
Refer to Testing and Inspection/Procedures.
- IDLE SPEED.





EMISSIONS CHECK: - EVAPORATIVE SYSTEM:
Charcoal canister and fuel tank vent system.
- PCV SYSTEM:
Defective PCV Valve or Solenoid.