The IAC controls idle speed, and won't cause misfires, but will cause improper idle speed & random stalling if the idle speed goes too low. IMO you should take a good look at the ignition system: coil pack, ignition control module under the coils, and the wires and plugs you just replaced, as one of them could be bad or improperly installed.

 

the packs are good
the wires and plugs are good
i havent checked the ignition module cause its starts first try now that i changed the ECT sensor that controls the fuel
its starts on -5 degree weather first try
if the ICM was out wouldnt it even start right? cause it does.
it also sometimes idles high while im in drive y is that?
this car is actin a ***
ima end up buy this 90 camaro with a rebuilt 305 for $1800 but i didnt really want a older car

 

It's your IAC. You already knew that, as Pete and myself have told you.

 

ok thnxs