Checking the Basics - Read Before Proceeding
Before using this section you should have done a diagnostic check of the on-board computer control system and verified;
- PCM operation
- There are no Diagnostic Trouble Codes (DTC's) stored.
SYMPTOMS
Verify the customers complaint, and locate the correct symptom in the table.
- Check the item indicated under that symptom.
VISUAL/PHYSICAL CHECK
This check should include:
- PCM grounds for being clean, tight, and in their proper location(s).
- Vacuum hoses for splits, kinks, and proper connections. Check thoroughly for any type of leak or restriction.
- Vacuum leaks at all mounting areas of the intake manifold sealing surfaces.
- Ignition secondary wires for cracking, hardness, proper routing, or carbon tracking.
- Wiring for proper connections, pinches, and cuts.
NOTE: The following symptom charts contain groups of possible causes for each symptom. These procedures are not necessarily meant to be done in consecutive order. If the scan tool readings do not indicate a problem, proceed in a logical order, easiest to check or most likely cause first.