Symptom Diagnosis

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

• Will Not Start (Cranks Okay)
• Difficult To Start (Cranks Okay)
• Engine Surges
• Rough Or Unstable Idle
• Excessive Fast Idle
• Engine Stalls
• Engine Lacks Power
• Engine Misfires Or Hesitates
• Engine Runs Rough On Deceleration
• Afterburn In Exhaust System
• Poor Fuel Mileage
• Detonation Or Knocking
• Fails Emission Test.