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 the BASIC TESTING article and diagnostic procedures in the TESTS W/CODES article were performed before diagnosing a symptom. Symptoms available for diagnosis include:

• Difficult Or No Start (Cranks Okay)
• Engine Misfires Or Has Lack Of Power
• Rough Or Unstable Idle
• Engine Hesitates
• Engine Surges
• Spark Knock/Detonation
• Poor Fuel Mileage
• Fails Emission Test
• Overheating