Cuts Out/Misses

Definition: Steady pulsation or jerking that follows engine speed, usually more pronounced as engine load increases. The exhaust has a steady spitting sound at idle or low speed.
- CHECK FOR MISSING CYLINDER BY:
1. Disconnecting IAC motor. Start engine. Remove one spark plug wire at a time, using insulated pliers.
2. If there is an rpm drop on all cylinders (equal to within 50 rpm), go to "Rough, Unstable, or Incorrect Idle, Stalling" symptom. Reconnect IAC motor.
3. If there is no rpm drop on one or more cylinders, or excessive variation in drop, check for spark on the suspected cylinder(s) with J 26792 (ST-125) Spark Gap Tool or equivalent. If no spark, see Ignition Section. If there is spark, remove spark plug(s) in those cylinders and check for:
- Cracks
- Wear
- Improper gap
- Burned electrodes
- Heavy deposits
- Perform compression check on questionable cylinder.
- CHECK:
- Spark plug wires by connecting ohmmeter to ends of each wire in question. If meter reads over 30,000 ohms, replace wire(s).
- Ignition coil and secondary voltage using spark tester J 26792 (ST-125), or equivalent.
- For restricted fuel filter. Also check fuel tank for water.
- For low fuel pressure. See CHART A6. Chart A-6 Fuel System Pressure Test
- Check for proper valve timing.
- Perform compression check on questionable cylinder(s) found above. If compression is low, repair as necessary.
- Visually check distributor cap and rotor for moisture, dust, cracks, burns, etc. Spray cap and plug wires with fine water mist to check for shorts.
- Remove rocker covers. Check for bent pushrods, worn rocker arms, broken valve springs, worn camshaft lobes.