Idling problem

[LxVert]

Hey guys,

I have a slight problem, when i start my car up it will idle at about 700 rpms, after driving the car for a couple minutes then stopping at a light for say, it will idle at 1500 rpms, but if i turn the car off then right back on the idle will be right at 700 again. Im so lost on what could be causing this

1990 5.0

 

[Quijibow_69]

Your idle control motor might be bad. I had the same problem, except when I started mine up it would almost stall and it would sit at 1500 RPMs when I was at a stop sign or light. I just replaced mine and it fixed my problem. I got mine from www.50resto.com. It was around 70 bucks, but you might be able to get one cheaper from EBay or Pep Boys or something.

 

[RYC CUKR]

before you replace the IAC go ahead and clean it.

Unplug it and unbolt it from the TB. Most of the time it has a bunch of carbon and gunk in there. Clean it out with some TB cleaner and see if that helps. Also take a can of starting fluid and spray the gaskets and vacuum hose connections on the intake to make sure that you don't have a vacuum leak as well.

Here is a nice write up on cleaning the IAC and some other things to check when you have idle issues

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

 

[jrichker]

Most certainly clean the IAC, and if that doesn't work, replace the TPS. See the Sticky " Help me create the Surging Idle Checklist" at the top of the forum for more help.

 

[LxVert]

Thanks guys for the info, i will clean everything really well then let you know how it comes out