My car has been idleing weird for a week now. It'll idle from 900 to 1100 then it'll drop down to as low as 200 and eventually die on me. We replaced the mas air sensor yesterday and it's still doing it. I put in a K&N filter in the air box, but it ran fine for a week. Anybody know what the hell is goin on?

 

need more info..what year? what codes are you getting?

 

How does the IAC look? Has it been cleaned lately?

 

http://www.muscularmustangs.com/maintain.php

 

Same problem here found out my IAC motor was shot....


also check for vac leak .........

 

First off whats an IAC? The motor is spotless all way around. It's only got 5,000 miles on it. I didn't put it in tho. It's still doing it but not as bad with the new mass air sensor. It's a 91 Mustang with 3.73 gears, cam, heads, and intake manifold if that helps. Also running it straight off the mufflers for now. Waiting for my exhaust.

 

Idle air control motor!! Located on your thottle body!!

Is your sig big enough? [&:][&:] https://mustangforums.com/announcement.asp?id=8

 

Mine did something like that and was told it is called "hunting idle" for me it was the TPS voltage (Throttle Position Sensor on the side of the throttle body) it was REAL touchy, only a smidge of movement made a big difference, but getting it right fixed mine. IIRC it was 1v but its been awhile so that may be off.

 

thanks, i'll check it out. Yeah i my sig is too big. I've been trying to resize it but it doesn't change! I'll just take it off.

 

Does it do it when it's warm aswell? Could be quite a few things, vacuum leak, o2 sensor, tps, iac.

& here is a resized image.

http://img140.imageshack.us/img140/8...ngspeeddv7.jpg

will look this big...