89stangconvert

i have an 1989 mustang 5.0 and ever since i replaced the intake and throttle body the car has been idling at 2000 rpm. i adjusted the idle screw..not the problem. i was thinking it is a vacumm line becasue everytiem i shut the car off i hear a hissing noise. when i took off the intake i also noticed some cracked vacumm hoses bud put them on anyway. could it be the vacumm leak or a faulty iac motor or sensor or any other sensor that has to do wiht the air intake

tchamber

Maybe you installed the IAC backwards. Double check

89stangconvert

the sensor part of the motor is facing down and angled to the left looking at the engine from the front of the car

tchamber

OK, there are 2 places on the tbody to adjust the idle, you have the throttle screw, which you said you adjusted. Is it a new tbody? Even if it isn't check the throttle-stop screw, it's on the outside of the tbody with the linkage, the throttle plate might not be closing all the way.

silver91gt

take off the tube going to the throttle body and see if the throttle blade is closed.
it should almost be closed.
and you cant put an iac on the wrong way.

tchamber

My aftermarket IAC could, I did it for about 1 min and the idle was high but it was supposed to mount opposite of stock, which I didn't do first. LOL.

silver91gt

it doesnt make sense, since there is a valve inside that opens and closes to regulate how much air enters the engine. it shouldnt matter which way it is on there.
and I didnt know there is an aftermarket vendor for those, who makes it?
I am jsut curious, not trying to be an ***.

tchamber

I think mine is Borg-Warner, maybe Bosch. I bought it at Autozone.com. It can bolt in backwards, but the valve has to be poisitioned properly...