IAC delete?
Thread Starter
Intermediate
Joined: Aug 2006
Posts: 33
Likes: 0
From: Colorado Springs Colorado
IAC delete?
I have been having a hell of a time getting my 88 to run consistantly. I only drive it about 1 time a month. I have a built 383 with a 58mm BBK TB a LPE Superram, GMPP big port lower intake, 36 lb injectors, EDEL Etec 200 heads ported and polished, 11.5 CR and a LT4 Hot cam. I engined dynoed it before installing it in the car on a MS management system it made 518 hp.
Long story short we didnt use the IAC with the Megasquirt and it ran great on the dyno. Once in stalled in the car it runs like CRAP!!! Even with a revised chip. I was just tired of it all and was about to install a carb setup yesterday. So I checked for bad connections, vacume leaks and the timing one last time. I just happened to unplug the IAC on a crazy guess and now its a completely new car. It runs great!!! Does this make any sense?
Long story short we didnt use the IAC with the Megasquirt and it ran great on the dyno. Once in stalled in the car it runs like CRAP!!! Even with a revised chip. I was just tired of it all and was about to install a carb setup yesterday. So I checked for bad connections, vacume leaks and the timing one last time. I just happened to unplug the IAC on a crazy guess and now its a completely new car. It runs great!!! Does this make any sense?
Last edited by 500HPC4; Feb 12, 2007 at 04:54 PM.
Intermediate
Joined: Feb 2007
Posts: 28
Likes: 0
From: Joplin MO
Let me make sure I understand correctly, you ran it with a megasquirt on the dyno, then when you installed the engine, you used the stock ecm with a chip, right? Just guessing here, but maybe there was a mistake made when burning the chip, or possibly there is something wrong with the IAC motor itself, or even possibly the wiring to it. There is a lot of stuff in ecm program that pertains to the IAC, so maybe it just wasn't setup right when the chip was burned. I haven't done any chip burning myself, but I've been reading a lot about it lately as I will be installing a monster engine soon and I'll have to tune the ecm for it.
Thread Starter
Intermediate
Joined: Aug 2006
Posts: 33
Likes: 0
From: Colorado Springs Colorado
Yes, you have it exactly correct. I have also tried 2 different IAC motors as well as attempted to set the min air and IAC pretty much everytime I drive the car. I would install the megasquirt but I really dont know how long I will keep the car and I think it would scare off a lot of buyers. I havent burnt any chips either but I have been doing a bunch of reading. The chip was done buy a local with years of expreience. I am going to try the ECU in another car tonight to see whats up. I have a feeling it is in the wiring on my car.
Will it hurt anything if I just leave it unplugged? The IAC really hurt the performance while driving too it would go rich to lean all the time. I will log it with my LM-1 and the IAC unplugged to see whats going on but it feels REALLY strong while unplugged.
Will it hurt anything if I just leave it unplugged? The IAC really hurt the performance while driving too it would go rich to lean all the time. I will log it with my LM-1 and the IAC unplugged to see whats going on but it feels REALLY strong while unplugged.
Last edited by 500HPC4; Feb 12, 2007 at 04:51 PM.
Thread Starter
Intermediate
Joined: Aug 2006
Posts: 33
Likes: 0
From: Colorado Springs Colorado
Thanks! That's what I planned on as the down side. ECU works fine in the other car and I still have the same problem with the stock one in mine.
Unless someone can tell me that Im gonna kill my engine I guess Ill just leave it unplugged. Its almost like the stock IAC wont react fast enough to the engines new air needs. I see that LPE sells a special IAC for the Superram has anyone used it?
Unless someone can tell me that Im gonna kill my engine I guess Ill just leave it unplugged. Its almost like the stock IAC wont react fast enough to the engines new air needs. I see that LPE sells a special IAC for the Superram has anyone used it?
Last edited by 500HPC4; Feb 12, 2007 at 09:30 PM.
