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 article in this section were performed before diagnosing a symptom. Symptoms available for diagnosis include the following:

• Hard Starting (Cranks Okay)
• Engine Surges
• Lack Of Power, Sluggish Or Spongy
• Detonation/Spark Knock
• Hesitation, Sag Or Stumble
• Cuts Out, Misses
• Rough, Unstable Or Incorrect Idle
• Poor Fuel Economy
• Excessive Exhaust Emissions
• Engine Diesels
• Engine Backfires