I have a '92 F-150, 5.0 (fresh rebuild), E4OD (also fresh rebuild). As soon as it starts, it runs up to about 1500 rpm and stays there until I put it in gear and then it goes down a little from the added load. I've replaced alot of things (sensors, fuel press. regulator, etc.), and checked and double checked other things (timing, etc.). I was reading some other postings and started to realize that I might be missing simple things like the gas pedal being partially stuck. The only thing I haven't gotten into yet is the EGR stuff. If anyone has any suggestions, please let me know. And I mean any, from the simplest to the worst case.
P.S. I know its not the idle screw because its turned all the way out.

 

I would pull the codes first to see if they tell you anything is wrong. If you have a vacuum gauge check the vacuum, you could just pull your vacuum lines off the top of the intake and plug the ports and see if that changes anything. If it runs better then put your lines on one at a time till the problem starts again, look at the line you put on that started the problem. Check the upper intake gasket, if the gasket is ok and the upper intake looks good no cracks then I would check the throttle body to make sure the butterflies are closing all the way and the throttle cable is working ok. Clean the idle air bypass/control valve on the side of the throttle body. If that is ok then I would set the idle. To set the idle, warm up your engine or wait till you go out on a pretty good drive and then:

1. Disconnect the IAC (Idle air Control) solenoid, if the engine dies turn the throttle stop screw till it will run. I went to the hardware store and got a screw that had a hex head on it because mine was not adjustable.
2. Set the idle where you like it, 750-800 worked best for me.
3. Turn off the engine and set the TPS (throttle position sensor) from .96 to .98 not .998 or .996. The TPS is on the bottom of the throttle body so you have to take the throttle body off, I was able to take off the top coolant hose and plug it no problem, this allowed me to flip the tbody and get to it. (The 2 wires to probe are the Black and Green or on some models the Gray/Red and Gray/White.) To adjust it just loosen the 2 screws slightly and twist it, one way the voltage will decrease, the other way the voltage will increase, I had to take mine off and egg out the end holes to allow it to twist. If you can't get the voltage to stay steady your TPS may be bad. This may take a couple tries because it may move a little when you tighten it down.
4. Disconnect the negative battery cable for 15-20 minutes. You can put your throttle body back on while you wait for the computer memory to clear. After you take the - battery cable off you can turn the lights on and off a few times to help purge remaining electrical current.
5. After you get everything back together and it has been 15-20 minutes, reconnect the IAC solenoid connector, put the negative battery cable back on and restart the engine.

I found I could make small idle adjustments after the initial proceedure above by just unplugging the IAC connector, setting the screw and plugging it back in and double checking the TPS voltage. As long as the voltage is below 1 volt you are ok. Hope this helps.

 

Thanks for the laundry list, I'll try all of that this weekend if the weather permits.