Cuts Out/Misses
DESCRIPTIONSteady pulsation or jerking that follows engine speed, usually more pronounced as engine load increases. The exhaust has a steady spitting sound at idle or under a load.
INSPECTION
Perform careful visual (physical) check of the following:
1. Inspect the spark plugs and spark plug wires.
2. Inspect the distributor cap and or rotor.
3. Inspect the ignition coil.
4. Inspect for restricted fuel filter and low fuel pressure.
5. Inspect for contaminated fuel.
6. Inspect for incorrect valve timing and or compression.
7. Inspect for bent pushrods and or broken valve springs.
8. Inspect for worn camshaft lobes and or rocker arms.
If ignition system is suspected of causing a miss at idle or cutting out under load, visually inspect ignition system for moisture, dust, cracks, burns, etc. Spray plug wires with fine water mist to check for shorts. For further inspection refer to Refer to Diagnostic Charts / Chart C-4.
Fuel Injectors and Connectors
1. If above checks did not correct problem, check the following:
^ To determine if one injector or connector is faulty, disconnect injector 4-way connector. On the injector side of the harness, connect ohmmeter between the B + circuit and the injector drive side of the harness for each bank of injectors. Because each bank of injectors is wired in parallel, an ohmmeter should measure about 4 ohms. If the reading is 6 ohms or greater, an open circuit is likely the cause. If the reading is 2 ohms or less, a shorted circuit or injector is likely. Reconnect injector 4-way connector.
2. If either ohm reading is out of range, perform the following:
^ Disconnect all injector harness connectors. Connect J 34730-2 Injector Test Light or equivalent 6 volt test light between the harness terminals 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.
^ Inspect injector balance. Refer to Diagnostic Charts / Chart C-2A.