Symptom Diagnosis

Symptom checks cannot be used properly unless the problem is actually happening while the vehicle is being tested. To reduce diagnostic time, ensure steps in BASIC TESTING and TESTS W/CODES (if applicable) articles have been performed before attempting to diagnose a symptom. Symptoms available for diagnosis include the following:

• Rough Idle
• Poor Fuel Mileage
• Erratic Timing Advance
• Timing Not Affected By Vacuum
• Engine Fails To Start
• Engine Backfires, Fails To Start
• Engine Continues To Run With Key Off
• Engine Starts, Then Dies
• Hard Starting
• Poor High Speed Operation
• Ping Or Knock On Acceleration