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 Inspect and adjust.
Fuel Injected Check air/fuel ratio.
Check fuel pressure.
(check vacuum line and return hose)
Incorrect idle speed Check and adjust idle speed if needed.