On my 91 chevy full size p/u i got a rough idle, its not lopey or anything like that its just like its missing, I recently replaced the plugs/wires/fuel filter/open element/cap/rotor to try to fix the problem, but it didnt do anything, its just got better throttle response, could it be the IAC? is there anway i could check it to see if thats it, and how much do they generally run?

oh by the way its a 350,tbi

 

There's a good tech article on the site about resetting the IAC. They are about $40.00.

 

cools, thanks