Weird idle problem

vaprobe87

Registered User
Just started having a wierd idle problem on my SC. I had been driving the car today with no problems. Put about 140 miles on it. I got home and let it set for about 20 minutes and then started it back up to go to the car wash. When I started it the idle instantly jumped up between 2500 and 3000 and stayed there. I shut the car off and air that sounded like it was being pushed back out of the intake.

I was checking for vac leaks and had someone else crank the car. As soon the car started I noticed the bypass valve opened all the way up. I just started with SCs so im not sure if it supposed to do that but I was thinking it has always been closed when I was under the hood with the car running before.

Any idea what the problem can be? If it is the bypass how hard is it to change or fix.

Here is a link to a video of it cranking up and shutting off.

http://www.youtube.com/watch?v=4LZlfVsSeTU
 
possible

my first thought when reading was IAC others may have better ideas. take it off clean it up .. or replace
 
my first thought when reading was IAC others may have better ideas. take it off clean it up .. or replace
same problem with my '94 my question is why the check engine light come out and when i driving the light turn off and came back again any ideas thanks. :)
 
I agree with IAC. Try unplugging it. It may not want to idle unplugged so you may have to use the peddle to keep it running.
 
Thanks for the help :D

So if I unplug it and it does not rev up then it is the IAC but if it still does it is something else?

What does a IAC cost normally if it needs to be replaced?
 
Yup to the first question. I think they are 50-100 bucks. I think advance auto carries them or the dealer. Might as well get a new gasket with it.
 
Part number for the sensor is 21762 at Advance. Lists at $58.79 here in Roanoke.

I have a stock pile of em if you need one used for a little less...could toss it in the mail to ya.

PM if need.

-Tim
 
Ok, so I unplugged the IAC and cranked the car. It seemed like it was idleing normal but was constantly making the weird noise through the intake like it did when I shut it off before. I cleaned the IAC with some throttle body cleaner but Im going to have to get a new gasket before I can put it back together and test it. The old gasket just crumbled into peices when I took it off.


If cleaning it doesnt help, is it safe to drive the car with the IAC messed up like that untill I can get a good one for it.


Tim Groth, I sent you a PM.... Thanks :)
 
I agree that the IAC valve is the problem. Cleaning them is usually a wasted effort, and if you don't have the $ to buy a new unit & gasket from Ford, just buy a used Ford one from someboby here. I've seen several of the non Ford IACs fail shortly after installing, and some that didn't work at all.

David
 
Ok, so I unplugged the IAC and cranked the car. It seemed like it was idleing normal but was constantly making the weird noise through the intake like it did when I shut it off before. I cleaned the IAC with some throttle body cleaner but Im going to have to get a new gasket before I can put it back together and test it. The old gasket just crumbled into peices when I took it off.


If cleaning it doesnt help, is it safe to drive the car with the IAC messed up like that untill I can get a good one for it.


Tim Groth, I sent you a PM.... Thanks :)

Replied - we need to set something up sometime to get this I-81 Corridor group in this area together. Maybe meet for wings in Christiansburg or something.

-Tim
 
Well, finally tracked down a gasket for the IAC and threw it back in the car. It fired right up and now idles better than it has since I got it.

When i first pulled it off the inside of it was black and you could tell it was gummed up bad. I sprayed it with throttle body cleaner untill it looked brand new inside LOL.

Tim, I will probably still take one of the IACs that you have after I get paid next week just in case I have more trouble out of mine.

Thanks everybody for all the help :)
 
Replied - we need to set something up sometime to get this I-81 Corridor group in this area together. Maybe meet for wings in Christiansburg or something.

-Tim


Im up for meeting a few other SC owners. Besides mine I have only ever seen 2 other SCs in person around here. Christiansburg is only about 1 1/2 to 2 hours away from me so I can do that pretty much any Thursday or Friday. Those are the only days I have off work.
 
Im up for meeting a few other SC owners. Besides mine I have only ever seen 2 other SCs in person around here. Christiansburg is only about 1 1/2 to 2 hours away from me so I can do that pretty much any Thursday or Friday. Those are the only days I have off work.

I have a few SC's just south of you.
 
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