Found out what was wrong...

[korbendallas68]

Okay, so my car was pissing me off enough, so I brought it into a repair shop. The problem they said was that the ECU set the IAC valve to WOT all of the time!! Christ. How does that friggin happen?!? So he fiddled around with the timing of it or something (don't remember), and now it starts without me pressing the gas, and it idles perfectly(doesn't die after a fast acceleration). Anyone have an idea of how that happens??

[jweir22]

Well that makes sense cause at wide open throttle the IAC plunger would have had that hole shut off so at idle you might be okay but gradually under normal load your car would be starved of air.Did he replace the IAC or is it fine and was just the Computer.

[korbendallas68]

No he didn't replace the IAC. I did before I brough it in. Twice!! What friggin waste of money. But yeah, I knew it had to be soemthing stupid like that... I just do not get how the comp set the IAC for WOT all of the time?!? Doesn't make any sense...

[v6h.o.]

somehow it "relearned" the wrong IAC idle possition.

what the PCM does is monitors the IAC for how many counts to always set the idle at that particular count. (number between 0-100 IIRC) and upon the initial startup it fluctuates the idle a bit finding that sweet spot of where the engine idles where its supposed to. it then puts that number in memory so to speak and on startup thereafter it comands the IAC to a range around that number, after start up it will fine tune the idle to that specific IAC count or a diffferent one if need be to maintain the proper idle.

somehow your PCM either relearned the wrong IAC count and needed to do a new relearn or something caused the pcm to just start setting it there...

[korbendallas68]

I unpluged the ECM fuse many-a-times to reset it. I brought it to the stealership a while ago to fix a oil pan leak, they messed around with the ECU a bit, but they didn't fix it. Those bastards charged me up the ass to do nothing! wtf? Oh well I guess... It works great now!

[geoffinbc]

Resetting the ECM will not relearn the IAC.. There is a procedure you need a scan tool to do it.

[3100 MPFI]

I brought it to the stealership a while ago.....

I love that.

[v6h.o.]

I brought it to the stealership a while ago.....

I love that.

(dealership technicican..)

[korbendallas68]

Resetting the ECM will not relearn the IAC.. There is a procedure you need a scan tool to do it.

Damn it. Go figure! Then why the hell did the dealership not set it correctly? I saw the screwing around with the IAC when I went in there. Stupids bastards... Sorry, just a little pissy...

[geoffinbc]

LOL get TBI... I never have to worry :P

[Anonymous]

That must be why our POS van never dies (wish it would)..

95 Lumina 3.1 TBI

[geoffinbc]

Yea baby. Hardcore. That was the ONLY 3.1L (oh wait Isuzu had it too) with TBI and the only vehicle to have TBI for so long.

[Mac]

off of GM Service Bulletin No.:476510
To correct the IACV position information, perform an idle relearn procedure using a techline diagnostic tool. You can also manualy relearn the idle by following hte procedure below.

1. Remove the battery power for 1 minute. Restore battery power and place air conditioning controls (if equiped) to the "off" position.

2. Firmly apply the parking brake and block the drive wheels. Start the engine, shift the transmission to drive for automatics and neurtral for manuals.

3. Allow the engine to run untilll the engine cooling fan as cycled once, or a maximum of 10 minutes.

4. Turn the ignition key to the off position for at least 5 seconds.

5. Repeat Step 2.

6. Allow the engine to run for at least 5 minutes.

The correct IACV values for proper idle control will now be stored.

[korbendallas68]

But I did that, and nothing happened... I don't know. I runs really good now, but it doesn't go to the 1000 - 1100 rpms like it should when you first start it. It will gradually climb up to 900 - 1000 rpms but that takes a few minutes. Weird.