surging and high idle

[88foxresto]

got an 88 gt vert and the idle has never been right since i bougth it back in march of this year. I tried cleaning the egr valve and havent noticed a difference. im bout to convert to mass air over the hoildays while im out of school. any ideas would be great. i have heard many other ideas but havent asked anybody yet.

[capriracer86]

the iac will cause it to surge u can clean it out but sometimes that wont work i would replace the iac valve!!!

[88foxresto]

well thats another 50 60 bucks but i can wait till i get more money lol

[Wayne's 88 GT]

Def sounds like a IAC valve sticking......like capri said you can take it off and clean it.

[SVTSkip]

If all that fails, you can also try an IAC adjuster. I had to put one in my car, and it really saved my bacon !

[bonesgt]

Like said above, remove and clean the IAC first. Use carb cleaner to clean it out and a small wire brush.

[Blacksheep]

It could really be a combo of things, but the IAC is the first place i would start. I put a brand new one on my car, and it still surged, so i tried the space/adjuster, and it still surged, so it can be Vaccum lines, EGR, IAC, etc..... But like said above, start with the IAC, and for the idle, just turn the screw down a bit.

[Superstroke17]

SD cars are bad for vacuum leaks too. I can't say I've seen many sd cars that idled right myself. Going mass air would be your best bet.

[Stable]

Just make sure that you adjust it correct......With the switch off remove the wire from the IAC motor. Start the car and adjust the throttle stop screw untill you have the idle around 900-1000. Turn the car off and put the wire back on the IAC motor. Next start the car without touching the pedal. If everything is ok the car will start and have a high idle....in the next few seconds, the car will start to move the idle down to the correct postition. It is always a good idea to reset your IAC when ever you make a chage to the motor that chages the amount of air coming into the motor. This adjustment will center up the IAC so that it can keep the motor in its idle settings.

[88foxresto]

okay i will try all these things tomorrow morning. i did but a k & n cone filter on so that should have bothered the idle:yes1:

[SVTSkip]

The K&N likely leaned out your A/F ratio a touch, but it shouldn't have been enough to cause any idle issues. After you clean the IAC and adjust/reset your base idle, I'll be interested to see how things are progressing...

[88foxresto]

Just make sure that you adjust it correct......With the switch off remove the wire from the IAC motor. Start the car and adjust the throttle stop screw untill you have the idle around 900-1000. Turn the car off and put the wire back on the IAC motor. Next start the car without touching the pedal. If everything is ok the car will start and have a high idle....in the next few seconds, the car will start to move the idle down to the correct postition. It is always a good idea to reset your IAC when ever you make a chage to the motor that chages the amount of air coming into the motor. This adjustment will center up the IAC so that it can keep the motor in its idle settings.

okay the car would not even start this morning with the iac motor unplugged. so idk what the problem is now.

[Stable]

Run the stop set screw way in and then give it a try

[88foxresto]

:thumbsup1:bingo that did it. yea turning the stop in helped out alot. now it idles at 1100 rpm, right where i need it cause i got i new radio that draws tons of power. oh and do i need to turn the stop back in some?

[Stable]

Is this with the IAC motor unpluged? IF not run it in till the car will run with the motor unpluged, then follow the rest of the instructions

[88foxresto]

no this is when the motor is unplugged. when i first start it up it is about 4-300 rpms higher then eventually it comes back down to 1000.

[Stable]

sounds about right

[cmb570]

i know this is old thread,but.......


Once you make changes/replace IAC or clock MAF, unplug then replug....... Does the computer take awhile to relearn everything ? If so how long does it normally take ?

[Notch93]

i know this is old thread,but.......


Once you make changes/replace IAC or clock MAF, unplug then replug....... Does the computer take awhile to relearn everything ? If so how long does it normally take ?

Take it on a 10-15 minute drive, and you should be good.