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 and
power up fuel pump (engine OFF).
Fuel pressure should stabilize and
remain constant.
On MFI systems energize
each injector individually and note rate
of pressure drop. The drop rate should be
balanced across all injectors.
On TBI systems a visual check of the injector(s)
should not show signs of leakage.
^ DEFECTIVE SOLE-VAC THROTTLE POSITIONER
(CARBURETOR FEEDBACK).
Go to COMPONENT TESTS to diagnose the SOLE-VAC.
^ IDLE SPEED.





EMISSIONS CHECK: ^ EVAPORATIVE SYSTEM:
Charcoal canister and fuel tank vent system.
^ PCV SYSTEM:
PCV solenoid defective.