Symptom Diagnosis

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 article have been performed before attempting to diagnose a symptom. Symptoms available for diagnosis include the following:

• Will Not Start or Starts Hard Cold (Cranks Okay)
• Will Not Start or Starts Hard Hot (Cranks Okay)
• Engine Stalls or Idles Rough
• Engine Misfires or Hesitates
• Excessive Fast Idle
• Engine Hesitates On Acceleration
• Engine Lacks Power
• Poor Fuel Mileage
• Engine Diesels
• Failed Emissions Test