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Home › Cadillac › 1993 › Allante › Repair and Diagnosis › Engine Performance › System › Engine Controls - Trouble Shooting - No Codes › Symptoms › Backfire › Possible Causes

Possible Causes

  1. Spark Plug Wires

    Perform CHART 6D4-1: IGNITION SYSTEM CHECK under IGNITION SYSTEMS in SYSTEM & COMPONENT TESTING - ALLANTE article. Check for:
    • Crossfire between cylinders.
    • Wrong firing order.

  2. Fuel Quality

    Perform FUEL & AIR CONTROL SYSTEM DIAGNOSIS CHART 6C-1: FUEL SYSTEM CHECK in SELF-DIAGNOSTICS - ALLANTE article. Check for:
    • Low octane level.
    • Contaminates.

  3. Low Fuel Pressure

    Perform FUEL & AIR CONTROL SYSTEM DIAGNOSIS CHART 6C-2: FUEL PRESSURE CHECK in SELF-DIAGNOSTICS - ALLANTE article.

  4. Low Flow Rate Injectors

    Perform FUEL & AIR CONTROL SYSTEM DIAGNOSIS CHART 6C-3: INJECTOR FLOW/RESISTANCE CHECK in SELF-DIAGNOSTICS - ALLANTE article.

  5. Exhaust

    Check the following for restrictions:
    • Catalytic Converter.
    • Exhaust.

  6. Mechanical Causes

    Check the following mechanical causes:
    • Valves sticking in guides.
    • Excessive oil consumption.
    • Camshaft timing.
    • Erratic VSS readings.
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