i got a 94 z and i just installed a set of ported and ploished heads and intake ported to match. As i was installing i pulled my PCM out and got Madz28 to tune it for me. Now when i start it will not idle. It will rev up then come down(1000 rpm) and after a few seconds it just dies down to like 200 or 300 its real low untill it cuts off. I can keep it running by giving it a little throttle. I heard after a tune its takes a about a week of driving to get everything to relearn. I drove it roughly 100 miles and it hasnt cleared up. I have no vacume leaks and the scanner was saying the IAC was maxed out. I tried to adjust the idle screw on the throttle body but now it idles about 1500 rpm and after a while it does like it did before untill it cuts out. If i drilled a hole in the throttle body to allow more air in solve the problem?
I have comp cam 306 and the ported and ploished heads as long with other bolt ons.

 

More than likely,you need to adjust the IAC. Search will find instructions.

 

Or the IAC may not actually be working. The scanner reads the position the IAC valve is supposed to move to. There is no feedback to the PCM of the actual IAC valve position. Is the IAC valve hooked up? If so, Shoebox has a procedure for checking the resistance of the motor coils. Is it possible the IAC passage is clogged? What throttle body are you using?

 

The IAC is hooked up and when it does idle for a few seconds the numbers change to about where the supposed to be before dieing down then its maxed out again then the car cuts off. I had to pull everything off my intake and i looked to make sure everything was clean. Im using the stock throttle body and thats what i think might be a problem. But i have heard people still have problems so i dont know whats the problem.