Surges and/or Chuggles

DEFINITION
Engine power variation under steady throttle or cruise. Feels like the car speeds up and slows down with no change in the accelerator pedal.

CHECK
- Spark plugs. Check for cracks, wear, improper gap, burned electrodes, or heavy deposits. Also check the condition of the rest of the ignition system.

- Ignition timing. See Emission Control Information label.

- Proper ignition output voltage with spark tester J26972 or equivalent (ST-125).