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Home >> Chevrolet >> 2003 >> Corvette Base, 2D Convertible, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Trouble Shooting - No Codes >> Symptoms >> Engine Backfires >> Ignition System
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Ignition System

  1. Inspect for proper ignition voltage output with Spark Tester (J 26792).
  2. Remove spark plugs and inspect for the following:
    • Wet Plugs
    • Cracks
    • Wear
    • Improper Gap
    • Burned Electrodes
    • Heavy Deposits
  3. An improper spark plug gap will cause a driveability problem. Gap the spark plugs using a wire gauge gap tool.
  4. Determine the cause of the fouling before replacing the spark plugs.
  5. Visually and physically inspect secondary ignition for the following:
    • Ignition wires arcing to ground.
    • Ignition coils arcing to ground.
  6. Soak the secondary ignition system with water from a spray bottle. Soaking the secondary ignition system may help locate damaged or deteriorated components. Look and listen for arcing or misfiring as you apply the water.
  7. Monitor the Misfire Current Counters while driving the vehicle in the conditions that the misfire occurred. If a misfiring cylinder can be located, use DTC P0300 for diagnosis. See DTC P0300: ENGINE MISFIRE DETECTED in SELF-DIAGNOSTICS - 5.7L CORVETTE article.
  8. Inspect for loose ignition coil grounds.