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 BASIC TESTING and appropriate G - TEST W/CODES article were performed before diagnosing a symptom. Symptoms available for diagnosis include the following:

• Difficult Or No Start (Cranks Okay)
• Rough Or Unstable Idle
• Excessive Fast Idle
• Engine Stalls
• Engine Misfires Or Has Lack Of Power
• Engine Runs Rough On Deceleration
• Backfire In Exhaust System
• Poor Fuel Mileage
• Excessive Oil Consumption
• Abnormal Noise Or Knocking
• Fails Emission Test