The term 'throttle actuator' usually refers to the cruise control link to the throttle, so you should have one. Very unlikely to cause your problem, though.

You can test the airflow sensor pot by unplugging it. If your idle is then smooth, it is likely the problem. With it unplugged though, throttle response will be sluggish, especially off idle.

Steve

__________________
'91 MB 190E 2.3
'08 RAV4 Ltd 3.5
'83 Lazy Daze m'home 5.7