Has anybody here removed/plugged the IAC?

[someotherguy]

Whew...

 

[superdave]

Whew...

I know, right?

 

[letitsnow]

I am very much a fan of efi. Bought a new Polaris Rzr back in 2012. It starts and runs nicely whether it is 100, or -20. I race a Suzuki RMX450Z (which is fuel injected) in the woods Runs mint.

Again - I wasn't asking anybody's opinion on whether or not I should do this. Was asking if anybody had.

 

[Supercharged111]

Forgot to mention that you run the risk of the TPS not being in the required voltage range by setting the idle that way. Good way to break hard parts in the trans.

 

[Mike Duckworth]

I have a 1990 Silverado that I bought brand new, with in 6 months the IAC started raising the idle when you were just sitting at a red light. Chevrolet never could fix it so I ran the pintle on the IAC all the way in, unplugged the 4 conductor plug, taped it up and folded it back in the wire bundle. I drilled the aluminium plug out on the TBI were I could adjust the butterfly and raised the idle just enough so when the A/C cycled on the engine would not cut off, that was 28 years ago, it worked for me. I would really like to know what happened to that thing, back then I needed my truck for work. This was on a 5.7 lo5, 4l60 transmission , 1224777 ECM.

 

[MarkZ28]

My 89's iac doesnt work either. I adjusted the idle manually just a tiny bit up so it wouldnt die when I turned the steering wheel too fast. No check engine lights from it, do have one fir the removed EGR valve though. The tbi kind of sucks on mine, rather have a nice 4150 Holley and performance HEI distributor. Too bad Chevy went with a crude poorly performing(power wise) injection system instead of a real port injection system like Furd and Mopar did. Had it on Camaros, Vettes, and even slowpoke 3.8 Buicks. Tbi runs smoothly and will do the job ok , but no fun for modifying.

 

[Supercharged111]

My 89's iac doesnt work either. I adjusted the idle manually just a tiny bit up so it wouldnt die when I turned the steering wheel too fast. No check engine lights from it, do have one fir the removed EGR valve though. The tbi kind of sucks on mine, rather have a nice 4150 Holley and performance HEI distributor. Too bad Chevy went with a crude poorly performing(power wise) injection system instead of a real port injection system like Furd and Mopar did. Had it on Camaros, Vettes, and even slowpoke 3.8 Buicks. Tbi runs smoothly and will do the job ok , but no fun for modifying.

The numbers don't lie though. It made 210 hp vs what, 185 from its predecessor? In its time the performance was definitely there.

 

[MarkZ28]

But Ford and Dodge were quicker, so they were still better. Raced a few Fords and got beat every time. I had a 90 stepside, 350, suto, 3.42 locker, bought new. I know the Didge 360 would have beat it from driving a few and had a couple 360 Durangos. The previous carbed trucks were weak, for sure, but would have been easy to modify to make more than the tbi made. My 89 has 2.73 gears, otherwise same setup but no locker. It seems to be decent, will spin the rear tire easy off the line, lol. Still not "fast". I do have 3.73 gears and a Spartan locker to go in it. Also have some good 59cc aluminum racing heads, roller rockers, Victor intake, and getting more to help with the go faster part.

 

[jdla140]

Forgot to mention that you run the risk of the TPS not being in the required voltage range by setting the idle that way. Good way to break hard parts in the trans.

This. I've done this on a couple turbo cars that have aftermarket ECU's that are poor at controlling IAC valves. it works good once you've relearned TPS values. But with a stock ECU where you can't relearn TPS values, it could cause issues. Specifically with trans control like you said.

I'll say it usually works pretty well, but tuning can be challenging. Even turning the headlights on changes idle speed.

 

[L31MaxExpress]

Hadn't noticed that from cutting that piece off.

I noticed the same thing and alot more off-idle throttle response.