Symptom Diagnosis: Notes

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 were performed before diagnosing a symptom. Symptoms available for diagnosis include:

• Difficult To Start
• Surges
• Lack of Power
• Spark Knock/Detonation
• Hesitation, Sag or Stumble
• Cuts Out or Misses
• Poor Fuel Mileage
• Rough or Unstable Idle
• Backfire
• Dieseling (Run-On)