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 G - EEC TESTS W/CODES articles in the ENGINE PERFORMANCE Section were performed before diagnosing a symptom. Symptom checks are listed in order of probability, ease of accomplishment, and accessibility. Symptoms available for diagnosis are as follows:

• No Crank
• Hard Start/Long Crank
• Stall After Start
• No Start/Normal Crank
• Slow Return To Idle
• Idle Surge, Runs Rough Or Misses
• Fast Idle, Diesels/Runs On
• Low/Slow Idle, Stalls/Quits
• Stalls/Quits, Hesitation/Stumble
• Runs Rough/Misses
• Surge
• Backfires
• Loss Of Power
• Spark Knock
• Poor Fuel Economy
• Emissions Compliance
• Warning Indicator Lights
• High Oil Consumption
• Cooling System Runs Hot
• Cooling System Runs Cold
• Exhaust Smoke Or Smell
• Fuel Odor
• Engine Noise
• Vibration