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 TESTS W/CODES articles have been performed before attempting to diagnose a symptom. Symptoms available for diagnosis include the following. Recommended system and component checks may not apply to all vehicles.

• Engine won't start
• Difficult cold start
• Fast idle out of specification
• Rough idle when warm
• Idle RPM high when warm
• Idle RPM low when warm
• Stalling during warm up
• Stalling after warm up
• Misfire or rough operation
• Emission test failure
• Lack of power