Two additional total guesses:
The IACV is supposed to control idle. It's the gold can here:
Perhaps it's not functioning correctly, the electrical connections need attention, or it needs a cleaning (if possible, don't know.)
Next guess is the air flow meter:
http://www.iprimus.ca/~trauttf/temp/AFM/afm_body.jpg
It's got two fingers that slide on a track as a potentiometer, the more air flowing, the further the finger are swung across. The ends near the idle / full close section eventually get worn through and it doesn't meter correctly. My car is jumpy just off idle, especially noticeable rolling through a neighborhood in 3rd. It's not noticeable taking off from a stoplight though. It's not annoying enough in my car to bother, but I guess you can move the sliders in/out slightly to start on fresh parts of the tracks.