GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Tracker - 4WD 🢒 Engine 🢒 Engine Controls - 2.0L 🢒 Backfire

Checks

Action

DEFINITION: The fuel ignites in the intake manifold, or in the exhaust system, making a loud popping noise.

Preliminary Check
    • Refer to Symptoms .

Ignition System Checks
    • Check for adequate ignition coil voltage with a J 26792 spark tester or equivalent.
    • Check the spark plugs for any of the following conditions:
       - Any wet plugs
       - A terminal screw that is bent or loose
       - A ceramic insulator that has cracks, carbon tracking, or deposits
       - A tip insulator that has cracks, carbon tracking, deposits, or is loose
       - A center electrode that is loose
       - An incorrect spark plug gap that is too large or too small
    • Check for the correct ignition timing. Refer to Ignition Timing Adjustment .
    • Check for crossfiring between cylinders. Check for the correct routing of the ignition coil electrical connectors.

Engine Mechanical Checks
    • Check for any of the following engine mechanical problems:
       - An incorrect valve lash
       - Any broken or weak valve springs
       - A low compression
       - Any sticking or leaking valves
       - An incorrect valve timing
       - An incorrect or worn camshaft
    • Refer to Engine Compression Test in Engine Mechanical.
    • Check the intake and exhaust system for casting flash or other restrictions.

Additional Checks
    • Check for the proper fuel pressure. Refer to Fuel System Diagnosis .
    • Check the Service Bulletins for any updates or information.