Symptom Diagnosis

Symptom checks cannot be used properly unless the problem occurs while the vehicle is being tested. To reduce diagnostic time, ensure steps in appropriate BASIC TESTING article and TESTS W/CODES articles were performed before diagnosing a symptom. Symptoms available for diagnosis include:

• Engine Does Not Start (Will Not Crank)
• Engine Cranks, But Fails To Start
• Engine Backfires
• Loss Of Power
• Detonation (Engine Knock)
• Stalls At Idle
• Engine Runs Rough (Off Idle)
• Rough Or Unstable Idle
• Engine Misfires - All Conditions
• Poor Fuel Economy
• Excessive Emissions