low idle with intake mod

[tac0meat]

I have a 91 Eddie Bauer with the ohv. I've been wanting to modify my airbox (I already got a k&n drop in filter) and noticed there was a tube that goes from the airbox up to the grill. It also had another tube that comes off of the passenger side exhaust manifold, I'm gussin that its the EGR. i disconnected that whole tube from the airbox and reset my computer. when i started it back up it barely idled at about 500 rpm. i went ahead and hooked the tube back up but even with my engine warm i'm still idling at about 600 rpm in park. did i sereously screw something up or is something i can do to get my idle back up? any help would be appreciated.

 

[Maniak]

I can't think of how what you did effected the idle but the idle is controled by the AIC and the TPS.

The easiest way to check if your AIC is working is to remove the plug from the AIC and see if the idle drops.. (do this when the engine is not warmed up). If the idle drops then the AIC was working.. if not it most likely wasn't working. The AIC is a $70 part that is on the driver's side of the intake plenum held on by 2 10mm bolts. You can try cleaning it by taking it off and then removing the 2 screws that hold the two halves together. Now use some solvant(sp?) to clean it up.. let it dry and put it back together.

For instructions on checking the TPS check out http://mark.legendz.com/code124.html

If it still isn't working the next step (other than making sure you didn't knock any vacumm lines off) is to use a code scanner and check for any stores codes.

 

[tac0meat]

my engines hot right now so im just going to wait until tommorrow morning. now the AIC, im just wanting to make sure where and what it is, is it that "bypass" tube running parallel to the throttle body?

 

[rock883]

Hey Maniak, I am not trying to be all corrective, but isn't it the IAC (Idle Air Control) and not the AIC? In my Haynes manual it says the IAC.

tac0meat,
The IAC is the part that the little sheild(the one that says 4.0L on it)clips on to. It is a metal cylinder looking thing.

 

[Maniak]

AIC or IAC

I always thought it was the IAC (thats what I was taught by a chevy friend of mine) but the part store here has it listed as an AIC(air idle control). I guess we need to find out what Ford calls it to get the offical name that Ford uses.