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.
^ Perform careful visual check as described at start of Section B.
^ Check for missing cylinder by:
1. Disconnect 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 Section 6D for Intermittent Operation or Miss. If there is spark, remove spark plug(s) in these cylinders and check for:
- Cracks
- Wear
- Improper Gap
- Burned Electrodes
- Heavy Deposits
^ Perform compression check on questionable cylinder(s) found above. If compression is low, repair as necessary. See Section 6.
^ Disconnect all injector harness connectors. Connect J-34730-2 Injector Test Light or equivalent 6 volt test light between the harness terms, of each injector connector and note light while cranking. If test light fails to blink at any connector, it is a faulty injector drive circuit harness, connector, or terminal.
^ Perform the Injector Balance Test. See CHART C-2A.
^ CHECK:

- Spark plug wires by connecting ohmmeter to ends of each wire in question. If meter reads over 30,000 ohms, replace wire(s).
- Visually inspect distributor cap and rotor for moisture, dust, cracks, burns, etc. Spray cap and plug wires with fine water mist to check for shorts.
- Fuel System - Plugged fuel filter, water, low pressure. See CHART A-7.
- Valve timing.
- Secondary voltage using a shop ocilliscope or a spark tester J-26792 (ST-125) or equivalent.

^ Remove rocker covers. Check for bent pushrods, worn rocker arms, broken valve springs, worn camshaft lobes. Repair as necessary. See Section 6A.