- When to Use This Section

BEFORE STARTING
1. Before using this section you should have performed the DIAGNOSTIC CIRCUIT CHECK and found out that:
^ The ECM and "Service Engine Soon" light are operating.
^ There are no trouble codes.

2. If the "Engine Cranks But Will Not Run", refer to Computers and Controls / System Diagnosis / Diagnostic Charts / Chart A4-3.

3. Verify the customer complaint, and locate the correct symptom below. Check the items indicated under that symptom.

4. Several of the symptom procedures below call for a Careful Visual Checks. These checks should include:
^ Check the ECM grounds for being clean and tight.
^ Check the vacuum hoses for splits, kinks and proper connections, as shown on Emission Control Information label.
^ Check for air leaks at throttle body mounting and intake manifold.
^ Check the ignition wires for cracking, hardness, proper routing and carbon tracking.
^ Check the wiring for proper connections, pinches, and cuts.

NOTE: The importance of the last step cannot be stressed too strongly, it can lead to correcting a problem without further checks and can save valuable time.