Cuts Out/Misses

Definition: Pulsation or jerking that follows engine speed, usually more pronounced as engine load increase. The exhaust may have a steady spitting sound at idle or low speed. May only happen with TCC applied, but this does not indicate a TCC problem.


^ Perform "Diagnostic Circuit Check - Calif".


^ Perform "System Performance Check - Calif"


^ Visual (Physical) Check:


- Vacuum hoses for splits, kinks and proper connections, as shown on Vehicle Emission Control Information label.


- Ignition wires for cracking, hardness and proper connections at both distributor cap and spark plugs.


- Wiring for proper connections, pinches and cuts.

- Check that 4-Terminal EST connector wires are not near spark plug wires. Four terminal wiring harness should be as far from distributor as possible.

^ Check for misfiring at spark plugs:

1. Disconnect and plug air cleaner and EGR vacuum hoses.

2. Check spark at all plug wires with J26792 (ST 125).

- If there is no spark on any cylinder, see "Ignition System Check", Chart C-4A.

- No spark at one or more cylinders:

^ Check spark plug wires by connecting ohmmeter to ends of each wire in question. If meter reads over 30,000 OHMS, replace wire(s). If wires check OK, or

- Spark at all cylinders


^ Visually check distributor cap inside and out for moisture, dust, cracks, burns and check for arcing to coil mounting screws. With engine running, spray cap and plug wires with fine water mist to check for shorts.


^ Check for poor ground on integral ignition coil.


^ Remove spark plugs and check for cracks, wear, improper cap, burned electrodes and heavy deposits.


^ Check pickup coil in distributor with ohmmeter, and check for proper connections at module. Pickup coil should be 500-1500 OHMS and not grounded.


- If pickup coil checks OK, ^ Check for ignition dwell increase from low to high RPM by connecting dwell meter to distributor "TACH" terminal. If dwell doesn't increase, replace ECM.


^ Remove rocker covers, check for bent pushrods, worn rocker arms, broken valve springs, worn camshaft lobes. Repair as necessary.


^ Check for exhaust system restriction.