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
Restricted air cleaner Replace air cleaner element

Idle speed misadjusted Perform idle adjustment. Adjustments

Vacuum hose/carburetor/manifold leak Inspect and repair vacuum leaks, retorque manifold and carburetor base, check carburetor air horn screws. Specifications

Carburetor idle passages/adjusting needles dirty Clean idle passages, replace adjusting needles. Carburetor Replacement

Throttle valves sticking/worn throttle shaft Lubricate throttle valves, replace worn throttle valve shaft. Carburetor Replacement

Float leaking or misadjusted Replace leaking needle and seat. Carburetor Replacement
Perform float level adjustment.