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:

• Backfire Through Induction Or Exhaust
• Dieseling (Run-On)
• Lack Of Power
• Spark Knock (Pinging)
• Stalls/Quits
• Stumble/Hesitation During Acceleration
• Misses/Surges
• Idle Is Fast/Slow Return To Idle
• Idle Is Rough
• Engine Speeds Up
• Cranks Normally/No Start
• Cranks Normally/Slow To Start
• Poor Fuel Economy
• Exhaust Smoke/Odor
• Fuel Odor/Leaks
• Fails Emission Test