Problem

[Black87GT]

Ok, im not really sure what my problem is, but there is definetly one, lol

Anyways, when i start my car it seems to idle ok for awhile but then slowly decreases, and acts like its going to shut off, then it will jump back up, then go back down, then finally shut off and keep shutting off, but as long as your driving it, your fine, but as soon as you stop at a stoplight or stop sign for a little while it will shut off,

im not really sure what it could be, i thought with underdrive pulleys that maybe they were draining the battery so i replaced the battery and alternator (my dads fox had this problem) but still no use, and it still wants to shut off.. i went to get tires put on it today, and the guys at wal-mart couldnt get it to stay running either, i felt like such an idiot

So anybody have any suggestions on what i could do/try to get this problem fixed?

Any help would be greatly appreciated, and sorry no pics, the digital camera is at my grandparents.

[Black87GT]

Anybody have any ideas?

[68GTO]

Vacuum leak - sounds like a lean surge

[RyanM]

coolant temp sensor or iac motor

[Crix13]

IAC issues possibly does your car have a cam or have u changed the combo your running? heads intake?

Mine did that couldn't find a vac leak anywhere and checked and reset the tps with no luck then on corral in the one of the threads they have a idle check list on quick and easy fixes to get a fox to idle properly I went through the checklist

Cleaned the Iac then replaced
cleaned the egr and 10 pin salt and pepper shakers
reset and reset and reset the tps with no luck set the tps at .98

Finally one guy said every cammed fox he has owned has needed a little more air on idle and he takes a dremmel and grinds between the two passages open a little at a time till the car will idle at 1000 or so with a f-cam

I did it and it worked great !!!

[Macs Stang]

I would lean towards the IAC being faulty. the IAC is the tube looking piece that is on the throttle body. It has a wiring harness coming off of it. What you can do is start the vehicle (you may need a helper for this) and unplug the wiring harness going to the IAC to verify if it is good or bad. If it is good then the engine RPM will change. If it is bad there will be no change in RPM.

[Crix13]

I found thats almost impossible to do if the car wont idle steady to unplug it clean the iac and make sure its movement is smooth otherwise replace

[Black87GT]

Well i guess IAC it is, almost everyone that i have talked to about this problem has said IAC,

Could anybody post a picture of the IAC so i know exatcly what i am looking for..

And i have had people say to unplug the IAC to check, and other people say not to
So what is it, should i? or shouldn't i?
Also, is there any other way to check to make sure it is my IAC?


I really appreciate all the help from you fellow TCSers!!

[Black87GT]

Oh yes, before i forget, i also noticed that when my rpms go down and it sounds like my car is about to die, that the battery gauge also starts to drop way down, like the battery is killing the car, is this normal because the car is dieing?

Or is the car not getting enough juice to keep it running?

[Crix13]

mine did that battery thing too i think it cause of the underdrive pulleys

If u can get it to idle steady enough to unplug it and see if the idle changes or the car stalls when unpluged go for it

with mine the thing would surge and it was hard to get it to mellow out enough to check if it made a difference Then i got i new one and the idle was better but far from fix minor grinding and idle issues are done

[mustang cobra93]

Vacuum leak - sounds like a lean surge

On a mustang 5.0 it would idle high all the time if it was a vacuum leak, or bounce all the time, not after its warmed up...

[mustang cobra93]

Well i guess IAC it is, almost everyone that i have talked to about this problem has said IAC,

Could anybody post a picture of the IAC so i know exatcly what i am looking for..

And i have had people say to unplug the IAC to check, and other people say not to
So what is it, should i? or shouldn't i?
Also, is there any other way to check to make sure it is my IAC?


I really appreciate all the help from you fellow TCSers!!

IAC's were a big idle issue on speed density Fox's!!!! Clean it or replace it! Done

[Black87GT]

kk sounds like the anwser to my question is the IAC?

LoL

[Grenade]

Take it off and clean it with brake cleaner.

[Black87GT]

break cleaner?

ive heard a lot of different things, what is the number 1, best thing to clean something like this with, so i dont ruin anything??

Thanks TCS!