you may have a funky TPS with a bad spot or a funky AFM with a bad spot or the door is not moving freely. Like Knute said, take a good look at the intake tube and rubbers. The curved one at the throttle body cracks down between the pleats. Mine has a crack, I put a RTV silicon band-aid on it till I find a good one.
EDIT: sorry to drag an ancient thread to the top
