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.

Misfiring Cylinder

Using a scan tool, check for a misfiring cylinder.

Secondary Voltage Components

Check secondary voltage components for corrosion of electronic ignition (EI) module coil towers and spark wire ends.

Spark Plugs

Check spark plugs for cracks, broken insulator or improper gap.

Wire

Check wires for chafes or cuts.

Fuel

Check for low fuel pressure and fuel quality.

Injectors

Perform Injector Balance test to test for clogged injector(s).

Valves

Check for proper valve timing, broken valve springs or sticking valves. Perform Compression test.