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 measure the 02 sensor signal voltage.
Perform injector service (cleaning). Fuel Injector Cleaning Procedure
Check fuel pressure (check return hose). Testing and Inspection

Incorrect idle speed Check and clean throttle body. Throttle Body Cleaning