what is your idle set at? once you start playing with idle sensor stuff, it is a good idea to check it all. i.e., if you play with the idle set screw, you should re-adjust the TPS. now i dont think you did; just some general info for future reference.
what is your timing set at? just went through this with an S-10 (4.3L). the dizzy set bolt had worked loose and timing had become like me, retarded. truck ran like poo.
some have argued that the puter zeroes out the TPS at start up (IIRC, Stang and Two Birds is one person whom said that, and i respect what he says).
now if the car is having trouble just at idle, or with ancillary components on while at idle (i.e., a/c especially), that suggests the IAC. it is the cylinder lookin deal on the front of the TB. it lets air through the TB. one can check it with a dwell meter, but that is kinda impractical. if you want, clean it out. if it is restricted, that can cause problems.
some folks have run without it connected. i dont recommend it. they generally have to set the idle to 1000 or 1100 RPM to accomodate a/c load, etc.
i would really check out the IAC if you have not.
good luck.