Rough Idle
Check spark plugs, spark advance, ignition system wires and connections, starter solenoid for internal shorting (except 2.5L), and trigger wheel pin. See BASIC TESTING article. See SYSTEM/COMP TESTS article regarding the following procedures.
- Check MAP sensor circuit and vacuum hose.
- Check injector harness connectors.
- Check coolant temperature sensor for shorted sensor or circuit.
- Check for proper idle control system operation.
- Check for shorted, open or misadjusted TPS.
- Check EGR valve operation.
- Check for shorts or opens in oxygen sensor circuit.
- Check PCV valve operation.