I have a 2000 Expedition with 85600 miles. Up until this past Saturday, it has worked perfectly, but going to the football game in the morning, it suddenly wouldn't run at idle. I can start it and keep it running only if I keep my foot on the gas. I have to put it in neutral and keep my foot on the gas in order to pull up to a light or stop sign. If I keep it in drive, it will stall out as soon as I come to a stop. It does this whether the engine is hot or cold. Thinking it was the alternator and/or battery, I had them both tested at the local parts store and the battery was bad; I replaced it, but the problem persists. The attendant at the store suggested the idler (or idle sensor) needed to be fixed. Any other ideas? Thanks in advance for the help.

 

Sounds like it could possibly be the torque converter ..... I have seen this in older cars ...

 

Is it throwing any error codes or is the check engine light on.If so scan it for codes.Sounds like a bad IAC valve

 

IAC. Do a search on this forum for IAC or Idle Air Control valve. This little sucker governs airflow while the engine is at idle and the throttle plate is closed. If it's stuck closed, the engine dies unless you open the throttle plate by pressing the accelerator.

Which engine do you have?

 

Thanks for the help. I have a friend who runs the service dept at a local Ford dealership and he said the IAC valve as well. He is going to pick one up for me (good friend to have, huh?) and I'll get it fixed. Any suggestions or tips to replacing?

 

Easy to access on a 4.6 engine, a bit more buried towards the back on a 5.4

Detach the negative battery cable from the battery before removing the old IAC, as the engine computer has to be put into a learning mode to guage the proper amount of voltage needed to operate the new IAC. Removing the cable from the battery for a few minutes will provoke this learning mode.

Do another search on IAC replacement. Many have covered this ground.

 

You've probably fixed this already but I just changed the IAC valve on my '99 5.4 last week. Truck would start and then die immediately...if you feathered the gas pedal it would start and then be okay.

Did a search here on the forums and everyone said IAC. Went to PepBoys and got a Borg-Warner for $50. I pulled the battery cable off before I left to get the part, came back and swapped it out...took about 15 minutes to change it. No problems since.

The valve is directly behind the center of the motor, at the top. It sits just a little under the firewall. Remove the three bolts holding the plastic shroud on the top center of the motor and its directly behind there. It was a PITA to get to the bolts though, I used a ratcheting 5/16" comb wrench (I knew those ratcheting wrenches would come in handy someday ).

 

thanks for all the help from every one. I got an IAC at napa for $50 and it fixed the problem right away. this is such a great find, as this forum helped me save $200 at the dealer. I'll definately use this if anything goes wrong again (hope not).

 

How in the world can the TC possible affect the idle!?!

 

the TC locks up ...