I got my hands on a Holley TBI unit for cheep, some one bought it and found it was not what they wanted, it has no IAC. I figured that I could sell it for way more than I paid for it, but started thinking maybe I should just use it. So I started wondering is there was a way to compleatly tune the IAC out of the chip, and if so what tables would I change? I am running an 8746 ecm. I disconected my IAC on the unit I have now and adjusted the idle screw so more air went in the TBI, and turned down the TPS to the normal voltage to compinsate for the idle screw change, this worked nicely, it ran just like it did before i did it, well at least for a week and a half, then it was like the IAC moved on its own and the car would not idle, but it lasted that long, a whole tank of gas. So I think it work out but is there a certian thing I would change in the chip to make it right?

 

I originally had a holley without IAC on my car, and so I got a IAC from a 3.8L engine. These bolt to the outside of the TB, and so I made a metal plate to bolt to the IAC, tapped it for a couple of fittings, and hooked it into my PCV line with a "T". It worked fine, but i eventually got a holley TB with IAC and I like it better. If you try this, you may need to fiddle with the four wires going to the IAC to get it wired right.

 

Sounds like an idea, but I dont wanna have to do that, last resort definatly. Still would rather go without IAC if possible. More help and or input would be apreciated. Thanks in advance.

 

if it takes a screw in iac goto the j/y and get an iac and pigtail for $5.

 

Nope not even a hole cast in the unit, besides the tps is in the way even if there was a hole for one. Just wanna tune it out of the chip if possible.

 

You might go get one of the solenoids that bump up the idle on a carburetor and put that on. With that, it should start cold a little better and not run so rich.

 

There are 3 things you should do to make it so the ecm doesn't use the IAC. First have no IAC hooked up (duh), then zero out the "max IAC throttle follower steps", "max IAC steps final", and lastly zero out all your IAC steps vs coolant temp. I haven't done this yet but I probably should now that I fixed my fuel delivery problems. If I do it I'll post to tell you if that completely eliminated the commanded steps, I can't see why it wouldn't.

 

Thank you sir, as soon as my intake comes, i'll be all over that.