Rough/Unstable Idle or Stalling
Definition: The engine runs unevenly at idle. If bad enough, the vehicle may shake. Also, the idle may vary in rpm. Either condition may be severe enough to cause stalling. Engine idles at incorrect speed.POSSIBLE CAUSE ACTION
Throttle linkage sticking/binding Check and adjust throttle linkage and cable
Fuel metering ^ Check air/fuel ratio, (02 sensor voltage).
^ Perform injector service, (cleaning). Fuel Injector Cleaning Procedure
^ Check fuel pressure (check vacuum line and return hose).
Incorrect idle speed The problem is computer related.