Base Engine Misfire Diagnosis

BASE ENGINE MISFIRE DIAGNOSIS





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Part 2 of 3





Part 3 of 3

Engine performance diagnostic procedures should be consulted for diagnosis of any driveability, emissions, or Service Engine Soon lamp complaints.
- Refer to Engine Controls - General Information.
- Refer to Engine Controls - Fuel Injection (MFI). Check for any related service bulletins prior to extensive engine diagnosis.

IMPORTANT: The following diagnosis information covers common problems and possible causes. When the proper diagnosis is made, the problem should be corrected by adjustment, repair or part replacement as required.

This diagnostic table will assist in engine misfire diagnosis due to a mechanical problem such as a faulty camshaft or leaking head gasket. Base engine timing is assumed to be correct and, that acceptable fuel is being used. This table will not identify a crossed injector wire, faulty injector, coil, driver, etc., or any other component failure or perceived misfire with no driveability symptoms (e.g. chipped reluctor ring with a DTC set or Service Engine Soon Light illuminated). The On-Board Diagnostic System Check must be performed first in order to ensure the correct table is followed for diagnosis of a misfire. Refer to Engine Controls first, then, if necessary, refer to this table.