Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Engine Controls - Tests W/O Codes: Symptoms: Notes
Symptom checks cannot be used properly unless problem occurs while vehicle is being tested. To reduce diagnostic time, ensure steps in appropriate BASIC TESTING article and G - EEC-IV TESTS W/ CODES article in the ENGINE PERFORMANCE section below were performed before diagnosing a symptom.
Symptoms available for diagnosis are as follows:
- No Crank
- Hard Start/Long Crank
- Stalls After Start
- No Start/Normal Crank
- Slow Return To Idle
- Rough Idle
- Low Idle (Stalls On Deceleration)
- Hesitates Or Stalls
- Surge (On Acceleration Or Cruise)
- Backfires
- Loss Of Power
- Spark Knock
- Poor Fuel Economy
- Emissions Compliance
- Warning Indicator Lights
- Improper Transmission Shift
- High Oil Consumption
- Engine Runs Hot (Overheating)
- Engine Runs Cold
- Exhaust Smoke
- Sulfur "Rotten Egg" Smell
- Engine Noise
- Vibration
- A/C System Not Functioning (Lack Of Cooling)
- A/C System Always On
- A/C Clutch Does Not Disengage Under WOT Conditions
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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