GM Service Manual Online
For 1990-2009 cars only

Cuts Out, Misses Symptom

Checks

Action

DEFINITION: A steady pulsation or jerking that follows engine speed, usually more pronounced as the engine load increases. The exhaust has a steady spitting sound at idle, low speed, or on hard acceleration.

Preliminary Checks

    • Refer to Symptoms - Engine Controls .

Ignition System Checks

Important: Do not perform this test for more than 2 minutes in order to prevent damage to the catalytic converter.

Check for ignition misfire.

  1. Start the engine.
  2. Disconnect the fuel injectors one at the time.
  3. An equal RPM drop on all cylinders (within 50 RPM) indicates a common condition that is affecting all cylinders.
  4. Check for spark on the suspected cylinders with a J 26792 spark tester, or equivalent, if there is no RPM drop on one or more cylinders.
  5. If there is no spark, refer to Engine Cranks but Does Not Run .
  6. Check for the proper secondary voltage output with a J 26792 spark tester, or an equivalent. Refer to Electronic Ignition (EI) System Diagnosis .
  7. Inspect the spark plugs for correct operation and performance. Refer to Spark Plug Inspection .

Engine Mechanical Checks

    • Check for any of the following engine mechanical problems:
       - Faulty hydraulic lifter assemblies
       - Broken or weak valve springs
       - Incorrect valve timing
       - Incorrect or worn camshaft
    • Check the intake and exhaust manifold passages for casting flash.

Fuel System Checks

    • Check for a restricted fuel filter or incorrect fuel pressure.
    • Check the fuel injectors. Perform the Fuel Injector Coil Test Procedure and the Fuel Injector Balance Test Procedure. Refer to Fuel Injector Solenoid Coil Test - Engine Coolant Temperature Between 10-35 Degrees C (50-95 Degrees F) and Fuel Injector Balance Test with Special Tool .
    • Check for water contamination of the fuel.