fRankie03Mach1

Hey guys wats up? Having a little problem here with my 03 mach 1.

While coming to a stop RPM's stay about 1.2k - 1.3k then in a few seconds RPM decreases to the point car stalls out. I heard this could be my IAC valve. I cleaned it along with MAF sensor, but i heard about a test to check if the valve is working properly by disconnecting the 2 bolts and leaving the electrical connection on and put the key to the "on" position (without starting the engine), the IAC should move up or down, if it does its fine. Mine is moving down like not even a mm(you can hardly tell) and then goes right back to originally position.

I am replacing the valve anyway but i dont think its working properly or is it?

Mustang3GT07

I had the same problem in my Mach1. Do you have a intake on their?

When I installed my K&N Intake I forgot to re-install the screen in the intake tube and it kept doing the same thing yours is. I put the screen back in and problem solved. If you don't have a intake disregard everything I just said lol.

fRankie03Mach1

Ya i have the JLT Ram air intake. The screen is there, no holes in it. I even removed the screen and still does it, i put it back in there.

Thanks for the quick response.

Mustang3GT07

Ok next solution. Their were a couple threads on this I believe over on Mach1registry.com and some people said this happens in the stock tune from the factory and that the computer needs to be re-flashed and car needs to be tuned. A couple guys over their went and got their car dyno tuned and problem was solved.

03MachMe

mine does it as well. i just keep it in gear till i slow down enough that the RPMs are around 1k or so then put the clutch in and that makes it to where it wont stall. but im sure a tune would help

northbaseball22

i have JLT ram air w/o screen and im fine