5 Year Member
- Mar 3, 2010
Gotcha well the car was cold when I did that just wasn’t sure what the car was suppose to do when I unplugged it, but was idling at what it normally does.I believe it's all how you set the idle in the tune. On a cold motor, just about all stangs should need IAC assistance but once warmed up and at operating temp. If idle is adjusted with no IAC duty cycle needed, it'll idle fine on it's own. Once you add an additional load like the AC it'll kick up the IAC dc.
As far as the noise I'm thinking the noise could be the air flow being restricted or not allowed to flow around the throttle plate anymore due to unplugging the IAC. When IAC is unplugged it will completely close.