Well just out of curiousity (and a really bad low idle problem), I unscrewed the IAC today. I took it out and pushed on the end. The end with the spring attached won't budge. The dude at autozone told me it's supposed to go up when you push. . Is this normal? Thanks!

 

The "dude" at Ought-Tow-Zone is sorely mistaken. That's a really good way to ruin an IAC.

 

Is the IAC the little device inside the breather assemlby?

 

 

Thanks Vader.

I assume IAC means Idle Air Control.

 

on a tbi its the "thing that is connected to the bottom of the air cleaner, I zip tied mine to the firewall when I put an open element on, I'm pretty sure you can clean them

 

Yes, The IAC can be cleaned. Although i beleive your reffering to the IAT, or intake air temp sensor. I took the pintle out to clean & lube my old one to try to revive it. If you want you can jsut short pins A & B on the ALDL and the computer will eject the pintle for you.

To the origional poster:
As for the low idle, how low does it idle? The stock tbi's are set to have a target idle speed around 550 rpms or so. One sure way to tell that the IAC is bad is a lack of a high cold start idle and off idle bog when you go to accelerate.

 

My Idle is high when I start it up cold....seems normal. Idle's 650-700 in drive and 1000 in park...then after the engine heats up a little, it goes down to 500 in drive and about 600 in park (with jumping rpm's)......and yeah it does bog pretty bad when I accelerate when it's cold. Thanks a lot.

 

If you do clean the ICA be careful. Only clean the tip and never spray the whoel sucker down with anything like carb cleaner. You can ruin it. Mosttime the tips and where it seats just gets gummy.

Matt

 

That sounds about right for the IAC to still be working. If the engine is having trouble idleing then its probably something else thats causing it. The stock l03 should be able to idle down there since the cam is so small. You could try a replacement jsut to be certain, but, it may not fix anything if the iac was still working. If its getting sluggish like mine was then it can cause some problems.

 

Thanks for the input guys

dimented - any ideas on what it could be then? Sound like an EGR problem ?

 

Could be egr. A valve thats stuck can cause idle problems. What kind of vacuum does it pull at ilde when warm?

 

Don't mean to jack anyone's thread but I got a quick question: On the procedure for adjusting the IAC, where in the procedure do you REMOVE the paper clip from the ALDL port? I just don't want to screw up the ECM in any way. Thanks.

 

Short A to B

Turn key On

Wait 30 secs

Unplug IAC

Key off

Unshort A to B

Start engine and set min idle, TPS what ever.

Take car for test drive and exceed 35 MPH a few times, this forces an IAC reset, in the ecm code wise.

Stop and Recheck idle.

Things should be OK.
If the adjustment was fubar'd or there is some loose gunk it might take a redo.

Found this on another thread from GRUMPY. Vader also has the details but this is it.