Lumina idling problem

[RareGMFan]

Ok. I'm not new to rough starting or running problems, but I'm a bit stumped on this one. '93 Lumina Eurosport 3.1 that dies at idle, but runs fine otherwise and has absolutely no trouble starting. First thought was IAC, but we replaced that with 3 used ones, and they all do the same thing. Now the odd part is, when I unplug the IAC and let the computer fall back on default, she'll start up and run fine without keeping your foot on the peddle (this is what led me to believe it was the IAC). But I have a hard time believing all 3 IACs we've tried are bad. She was running perfectly fine before this. Here's what's been done before this problem even began:

 

Spark plugs

Spark plug wires

Ignition Control Module

Ignition coils (yes, all 3)

O2 Sensor

Fuel Pressure Regulator

 

The car has not had power killed to it or the ECM recently, so it's not an idle relearn situation. It's been to the mechanic a couple times, now. So far, they removed the plenum to check for vacuum leaks, and ran it on the computer diagnostics a couple of times. All they found was a broken PCV hose, but that didn't cure anything.

 

Here's what I'm thinking, but I don't know if these problems would cause these symptoms, and I was looking for some assistance. MAP sensor or TPS. Any input would be greatly appreciated!

[Euro]

mine idles kinda rough when it sits for a long time running. could be the fuel injectors(replacing those(($996))helped mine idle better) clean your throttle body, or plugs/plug wires is my guesses.

 

Id wanna know some other ones, cause mine still doesnt idle smoothly.

[god910]

You spent $1000 on INJECTORS??? For a parts car non the less!!!!

[RareGMFan]

Actually, problem solved. Like I said, we had changed everything else I could think of before this problem even started, so I was afraid of this. I wanted it to be a last resort, though. The computer was apparently bad. I figured something was up with it, because there's no way 3 IACs were bad, yet when I unplugged the IAC, it started up and idled by itself. So there you have it, folks. She's back to purring like a kitten.

[Slade901]

Actually, problem solved. Like I said, we had changed everything else I could think of before this problem even started, so I was afraid of this. I wanted it to be a last resort, though. The computer was apparently bad. I figured something was up with it, because there's no way 3 IACs were bad, yet when I unplugged the IAC, it started up and idled by itself. So there you have it, folks. She's back to purring like a kitten.

 

What did you get? A brand new Computer? or Remanufactured Computer? The Cost?

[Euro]

yeah whats the deal with the computer.