Symptom Diagnosis: Notes

Symptom checks cannot be used properly unless the problem is actually happening while the vehicle is being tested. To reduce diagnostic time, ensure steps in BASIC TESTING and TESTS W/CODES articles in the ENGINE PERFORMANCE Section have been performed before attempting to diagnose a symptom. Symptoms available for diagnosis include the following:

• No Start - Cold Engine
• Starts But Stalls - Cold Engine
• Hard To Start - Cold Engine
• No Start - Warm Engine
• Erratic Idle - Warm-Up
• Backfiring
• Incorrect Idle Speed
• Hesitation - Acceleration
• Hesitation - Coasting
• Knocking
• Engine Misfire - All Conditions
• Insufficient Engine Power
• Poor Fuel Economy
• Excessive HC and NOx