1999 Expedition will not run after it starts unless I use the accelerator to keep the RPM above 600. In other words it will not idle by it-self. Also the service engine light soon, has come on and does not go out.

Is there a sensor that needs to be changed or could it be a fuel filter? I thought maybe the injectors were dirty and ran a bottle of cleaner thru them, but no help.

 

First, welcome to FTE!!!!!

It sounds like you have a problem with your IAC valve. Try cleaning it first, before buying a new one.

 

I agree-- sounds like the IAC (idle air control), a valve located on the intake plenum tha t can be changed easily. I recommend that you have someone scan the computer to check for other possiables such as the ECT (coolant temp) sensor since you stated that the ses light was on. Most likely (95%) it is the IAC.

 

Thanks for the fast replies. Went to NAPA and bought a new IAC, $57 with tax. Now all I got to do is figure out the best way to get the old one out from under the firewall recess where the throttle body sets. Looks like a slow go with an open end wrench.

 

i had the same thing except it turn out to be the pcv hose connection in the back of engine had a crack in the rubber elbow at the end of line where it goes into engine. it was showing a 1143 code and 141 131 codes, you might check this

 

Got the new IAC installed today and that fixed the problem. Now if I can only figure out how to get the "Service Engine Soon" light to go out.

Thanks to all who replied.

 

Go by autozone and have them scan it. They can reset the light after they scan it.
Jimmy

 

Fordman063,
To clear your check engine light, disconnect your negative battery cable from the battery and let it sit for approx 10 minutes. This should reset your computer and reset the light as well.
Good luck