[Baneful]

I installed an accufab tb/p combo and experienced hanging rpm during shifts and while slowing down to a stop. I have a 5 speed manual. I did a search for it on google and found an install guide for the accufab and the fix for the hanging idle at stangpro.

The fix involved putting a 1/2 copper pipe cap with a 1/4 in hole in it before the black box on the iac line between then air intake and the tb. I put the cap in and the idle is ok with the ac on or off, the lights on or any other combo of the above. It drops rpm a lot faster now and decelerates more when off the gas.

I have a stumble at freeway speeds with the cc on. It seems to do it when the cc goes into coast mode and the car tries to decelerate and the cc kicks back on. Other than that the car drives fine and doesn't stall except one time after first installing it and having the ac on.

Does anyone else that has gotten the iac thing off ebay for the hanging idle experience this? I looked for the iac thing on ebac and couldn't find one. Is it just a plate that has a smaller hole in it and where does it install?

Thanks

[Garhfer]

lol the hanging rpm's are normal, it did that before you put the plenum and throttle body on, they come like that from the factory... what is the big deal with it hanging a little, so you're telling me you want to decelerate faster? lol I thought people who bought mustangs wanted to go faster not go slower faster... I'd just leave it alone before ya end up messing something up, I heard you can fix it with a good tune.

[Baneful]

Heh, I like accelerating just fine

I pulled it out just to make sure I don't damage something, but the hanging rpm thing is annoying to me . Call me weird I guess.

So are the ones they sell on ebay bad for the car? I thought I saw Timber had installed one w/o any problems?

[DrHolliday]

It does basically the same thing. All the ebay thing does is my smaller holes where the IAC bolts to the plenum.

You can do the same thing for dirt cheap. Just buy some gasket paper and trace the IAC gasket but make the 2 holes a little smaller. You can keep trying new ones with smaller and smaller holes until you get the engine to drop rpm's at the speed you like.

I do remember one person saying their exhuast sounded like a fart when they decelerated after they did this though. But I don't see how that could change too much. All it does is limit how much air goes past the TB to get a smooth idle.

[40thmustanggt]

try some seafoam!!! i heard this help's also.. im about to put my car in the shop to get my clutch replaced so when i get it back im going to seafoam it.. i'll let ya know by friday!

[Timber]

The gasket I bought off ebay fixed it completely, no farting exhaust note...

[2000stangGT]

reset your ecu, should go away in about 50 miles, mine did anyway...

[neckbonekat]

Is this the one you are looking for?

[ChrisJ]

Or you can have this fixed with a good tune...

Thats how I fixed mine...

[04GTAMPA]

sometimes the ECU will reset to accept the new airflow in a few days. Right now your engine is breathing more air than before, a lot more, so give it a couple of days...
Sometimes by adding and cutting pieces we intrude with the true benefit of the air flow.

[Baneful]

Originally Posted by neckbonekat Is this the one you are looking for?

Sweet, thanks. That was the one.

I had the car tuned when I got the sct. The guy was really nice and did 7 diff pulls getting my af mix right on for me. I didn't think to ask about the hanging idle at the time because I was still in the break in period on my gears and I was taking it really easy.

I will order those ones off ebay and use them untill I get my next tune and see if they can get rid of it then.

Thanks everyone

[Bullitt2797]

Originally Posted by 04GTAMPA sometimes the ECU will reset to accept the new airflow in a few days. Right now your engine is breathing more air than before, a lot more, so give it a couple of days... Sometimes by adding and cutting pieces we intrude with the true benefit of the air flow.

I had the same problem on my 02 GT. Mine fixed itself after a few days. Like he said, it just has to get used to it.