not the usual idle issue

[cbarr300]

Hey guys, I'm about to go outside and try and figure this problem out...but figured I'd start a thread to get some input whenever I come back inside.

Yesterday I was driving around and went to a carshow and then I went to my dads house to celebrate the 4th. The car was running 100% perfectly the whole entire time....

well.....

I went to start it up about 2 hours later.....and all of a sudden the idle was at 2000 and kept raising up to 3000 before I shut it off and said wtf.

I checked my throttle body to make sure nothing was hanging up and everything's good.

I retarded my timing a lot and it started to idle like normal....but had absolutely no power when I'd get on it.....car was running hotter, headers started glowing, uneven acceleration.

I got the timing light out and set it back to 10* base (with spout out), and the engine would creep it's way up to 3500 rpm rather quickly.....but the car felt like normal when I'd go WOT.

I did a quick check for vacuum leaks and am gonna check again in a few....but my vacuum gauge was staying rather steady.

btw, balancer is good. piston is at TDC when it should be.

any thoughts? I'm thinking IAC is at fault....guess I'll find out here shortly

 

[BlownFiveLiter]

I had basically this exact same problem about 2-3 weeks ago and it was very annoying since it started about halfway into my hour drive home from work. I tried everything I could, including resetting the base idle, checking for vacuum leaks, even cleaning the IAC. Nothing would get it to idle down, so I disconnected the battery and I'll be damned if when I reset the EEC, the problem wasn't gone! No explanation for it, but I do have a couple of codes I need to take care of (something about ACT voltage, and the other I don't remember).

 

[cbarr300]

I tried doing a kam reset...no go for me.

So you're still having issues with it?

 

[BlownFiveLiter]

I have no idle issues, for the time being anyway. I still have a couple of codes present, but I haven't felt like addressing them yet. That sucks about the no-go for the KAM reset. Maybe try unplugging the IAC and see if the idle drops down to normal. Mine actually didn't want to idle with it unplugged, so I had to constantly feather the gas to keep it going (no tools with me to adjust the throttle stop temporarily). The best I can do is offer a free bump for ya, as long as the usual suspects check out alright (vacuum leaks, IAC, no binding in the throttle or cruise control cables). Not too sure where to go from here?

 

[cbarr300]

I just took the iac off and covered the opening up....and it idled like it should.

guess I'm gonna get a new one

I'll post up with results

 

[cbarr300]

hey guys, I unplugged the iac....and the car started to idle like it should (instead of 3000 or so). The only issue this caused was a delay in throttle response (expected though)

does that mean that my iac is at fault?

 

[red95gtconvert]

^^^ Yes, I had the same problem as you and temporarly fixed it the same way you did. I installed a new IAC and problem solved. Throttle response was somewhat down with the IAC disconnected and the intake ports blocked off.

 

[Stanger007]

Sounds like a bad IAC - they will stick sometimes as they get old.

You can tap it with a hammer to unstick it.

My replacement IAC was from PepBoys - works fine. I may can get you the BorgWarner part # off the box if you need it - I think I put my old IAC in the box. AutoZone had the way wrong IAC listed.

Wes

 

[gcomfx.com]

You might try cleaning the IAC out. I've heard of guys cleaning them with carb cleaner around the plunger.

 

[cbarr300]

new one took care of it...pep-boys

thanks guys