Really weird high idle problem..

[XxHybridx]

So ive had this problem for quite some time now.
At first it started as my car idling at 1200-1500. And i mean, for a long time. Even after car warms up, idle still stayed very high.

Now the weird thing is. When it barely started, I could be going 50 mph, and throw it in neutral and the idle goes down to 850 and it stays there as long as I am coasting.
But when the car comes to a complete stop, the idle goes back up to 1500.

The thing is, that it wouldn't do this every day. On some days, the car idled perfectly. And i mean, throughout the whole day. Morning, and night, turned car off and back on.

Lately it hasn't had any good days. It just has the idle issue every day. And now the idle is between 1700-2000 :duh:. And when I am coasting it idles at about 1200 in N. then back up to 1700 when the car stops.

Ive read some older threads, and people said it might be the egr or the iacv. I even tried some bt cleaner to make sure the throttle body wasn't dirty.

Just wanted your opinions before i have to change the egr and iacv.

Thanks!

[s13-ghost]

Make sure there isn't any vacuum leak. Chek shouldn't be hard to chek.

[s13-ghost]

O n just clean the aicv no need to replace it might be just dirty

[240driftr]

im siding with s13-ghost. i had the same problem. my idle wud go up and down an it tuned out to be my iacv

[rocketpanda]

Actually I had this problem on sr and thought it was a leak because it was idling fine till I would put it in neutral and brake it would drop to 500. So what I did is adjusted through the throttle cable with a 14mm wrench and at the same time adjusted through the air control valve?? I think its called?? Lol but u use a flat head. Its an adjuster screw between cylinder #2. Thats how I fixed my problem. Another thing it might b is the intake manifold gasket. But try adjusting the idle before u go deeper into it. Hope this helps u out.

[XxHybridx]

cool thanks guys. ill give it a try. is there any easier to clean the iacv without taking the thing out? looks like a hastle lol.

[s13-ghost]

No its not that hard just unbolt u struggle a lil, if its ur first time removing it. But u should be good

[Om1kron]

most of the time the bypass valve that's in the aac gets stuck, this is either from the aac just being old or the electronics in it finally died. I've had this problem on my car since the timing was fixed. When my timing was off car was idling where it was supposed to.

Once I finally dyno'ed the car the IACV has taken a shit.

try running the car and unplugging the IAVC from the harness adjust the screw on it until it's idling at 1200 disconnected.

turn the car off and plug it back in, turn the car back on. If the idle doesn't fall to 8-900 and goes up to 1900-2000 rpms then the IACV is bad. (PERIOD)

Everyone on zilvia will tell you to adjust all of this unecessary shit, don't you'll make it worse. If the car ran fine and one day decided to run all retarded, this is 100 percent the problem.

I've been troubleshooting this for the past 2 months now trying to get to the bottom of it, and short of testing a new IAVC it's still not resolved. I am willing to bet 100 dollars that when I put a new IACV on my car and fire it up and adjust it, the problem will be resolved.

I did see an article somewhere on how to rebuild one but I cannot find it for the life of me otherwise I would give that a try.

You have to keep in mind how old your motor is and how old this piece of electronics is.

[ETHANOLED SR]

most of the time the bypass valve that's in the aac gets stuck, this is either from the aac just being old or the electronics in it finally died. I've had this problem on my car since the timing was fixed. When my timing was off car was idling where it was supposed to.

Once I finally dyno'ed the car the IACV has taken a shit.

try running the car and unplugging the IAVC from the harness adjust the screw on it until it's idling at 1200 disconnected.

turn the car off and plug it back in, turn the car back on. If the idle doesn't fall to 8-900 and goes up to 1900-2000 rpms then the IACV is bad. (PERIOD)

Everyone on zilvia will tell you to adjust all of this unecessary shit, don't you'll make it worse. If the car ran fine and one day decided to run all retarded, this is 100 percent the problem.

I've been troubleshooting this for the past 2 months now trying to get to the bottom of it, and short of testing a new IAVC it's still not resolved. I am willing to bet 100 dollars that when I put a new IACV on my car and fire it up and adjust it, the problem will be resolved.

I did see an article somewhere on how to rebuild one but I cannot find it for the life of me otherwise I would give that a try.

You have to keep in mind how old your motor is and how old this piece of electronics is.

I noticed this is an old thread but I am having the exact same problem. I'm gonna give this method a shot before replacing the AICV... I thought it might have been an ecu issue since I went auto to 5spd and only have the speed sensor hooked up on lower harness... Off topic but, another major problem I need to fix is my heater core flap door adjustment! This is gonna be a pain to get to but I'm hoping it'll fix my temp control switch issue. anyways thx for the input. We'll see how it goes.