Preliminary Checks

NOTE: If engine runs normally after ignition switch is turned to OFF position, check for damaged ignition switch or IGN RUN or VPWR circuit for short to power.

Check for vacuum leaks. Check for deposits on throttle plate. Check throttle linkage operation. Check for binding/sticking cruise control linkage. Check for air intake duct leaks. Check for leaking intake manifold gasket. Check Idle Air Control (IAC) or Exhaust Gas Recirculation (EGR) valves. Ensure vehicle is at normal operating temperature.