lately ive noticed that if i start my camaro up and dont touch the throttle at all for an extended time (1-2 min) it starts getting "confused"
what i mean is that it seems to loose the ability to keep a stable idle.
normally it idles right around 650 rpms just fine, but after awhile, it starts jumping between ~500 and ~750.
it will usually be from 500 to 750 and back in about 1.5-2 sec.
if i touch the gas or put a load on the engine it smooths back out.
if i let it go, it will get a bit worse then get better and stop altogether for a while only to start again later.
it does it warm and cold

anyone know what could possibly be the cause of this and what i should do to remedy this?
ive already tried to adjust the IAC motor and it seems to help the general idle quality but since i had never noticed the problem before, i cant say if it helped at all with the surging.
if i raise the idle up with the stop screw in the throttle body to about 750 or so, it wont do it nearly as bad if at all.

to me it seems like the computer/IAC motor cannot react fast enough and is getting caught in a YO-YO motion until i step in and tap the gas

 

would this be better in the tech/general board?