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 in the ENGINE PERFORMANCE 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
NOTE:
Systems and components listed under each symptom may not be applicable on all models.