Dieseling/Run-On

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

^ Visually (physically) check:
- Throttle linkage for binding or accelerator for being clear of obstruction.
- Carburetor choke, throttle linkage and fast idle cam for sticking.
^ Check carburetor choke, vacuum break linkage, throttle linkage and fast idle cam for proper adjustment.
^ Check cruise control for proper adjustment.
^ Check Fuel Cut-off solenoid operation.
^ Check engine idle speed. Both base and ECM controlled idle should be verified. See Vehicle Emission Control information Label.
^ Check ignition timing. See Vehicle Emission Control Information label.
^ Remove carbon with top engine cleaner. Follow instructions on can.
^ Check for engine overheating. Use "Scan" tool if available. Normal coolant temperature is 85-100°C, (185-215°F).
Check for:
- Low coolant.
- Loose fan belt.
- Restricted air flow to radiator.
- Restricted water flow through radiator.
- Restricted thermostat.
- Inoperative fan clutch.