Problem:
When I start the truck and drive away, lets say 5 miles, the truck wants to maintain a high idle. When I come to a stop, its almost like i'm holding the brake and gas pedal at the same time. When I put it in park, it goes up to 2.5krpm then surges and stays at 3krpms. Sometimes it goes away after a little while.

Replaced:
IAC valve, Fuel filter, Fuel pressure regulator, all vacuum lines coming from the "tree" in the middle of intake manifold.

I still have yet to replace the pcv valve. It's cold and the tubing is rock hard. I tried pulling on it but it wouldn't budge...

Also, I don't really notice any loss of power.

Thanks for the help!

PS
I also saw what looked like a little spot of fresh yellowish fluid on my driveway when I got home. I can't tell yet where its from. Hopefully its not a blown head gasket.. doesn't smoke while running but I need to check it out.

 

Just a guess. I would suspect the Throttle Position Sensor.

 

Forgot that part! I replaced the tps sensor when i first got the truck because of a cel code.

 

I have a couple questions.
Did you replace it with a Motorcraft part?
Did you set the voltage? Some say they're non adjustable but they are.
When you replace the PCV valve make sure it's a Motorcraft part as anything else will definitely cause a high idle issue. Been there done that.

 

The ECT could be misreading. It's on the standpipe above the thermostat.

 

I think the tps was motorcraft but I can't remember. It was purchased at Autozone.

Did not set the voltage.

PCV is not motorcraft either...

 

I'm not familiar with ECT. Can you elaborate on what it is and why it would cause high idle?

Thanks!

 

Engine Coolant Temp sensor. If it's not trading right it could fail to enter closed loop and it'll think it's warming up all the time and idle high.

 

i'm talking like 3000rpm+! Thats pretty high in this truck/engine.

 

I'm inclined to agree with Chris. If you have replaced the TPS with Motorcraft and it's still surging, I'd think it's the coolant sensor. You might as well start at the beginning with diagnostics and pulling codes: http://easyautodiagnostics.com/ford/...-of-articles-1
Do it right and save $