crazy idle STILL

I'm goin' NUTZ! I replaced the air idle adjuster in the throttle body and spray'd the whole thing out and have a new O2 sensor in this thing and it STILL acting like it has a mind of it's own. No air leaks noticed so far. My '90 either wants to rev up or just die at idle and it seems to almost lock in 4th gear and "push" me into traffic especialy when cold. I'm starting to think the computer is fried.....HELP?