I have a 2000 F-150 and just recently got transmission work done. It ran great for about a week then all of a sudden one day I started it up it idled fine for a minute then dropped below 500 rpms and just stalled out on me, now every time I try to start it, the rpms surge to 1500 then just stalls out now I can't get it started, it's my first f-150 so I don't even know what to begin to look for, please help.

 

Sounds like a defective idle air controller.

It won't even start if you hold the pedal down just a bit?

 

It starts and then immediately dies. I tried stepping on the gas and it starts to run norma for a minute but then the rpm's drop and then it stalls again

 

Get the codes checked at your local auto parts store.

 

When was the last time you changed the fuel filter?

You should probably do a fuel pressure test, there's a port on the fuel rail to connect a gauge, which can be borrowed from parts stores. Should be 28 to 40 psi.

Let's confirm - even with your foot on the pedal to hold it up to a high idle, it still stalls?

If it's not driveable, buy a code reader, they are under 20 bucks on Amazon.

 

Replace the IAC.
Classic symptom of start/stall when the air bled is blocked internally in the IAC.
There is no code for this fault.
Good luck.

 

Sorry I don't know how to make a new thread. IAC was just replaced but truck still won't stay running and the mechanic can't even figure it out. Anybody have any ideas of what it could possibly be? Any help would be greatly appreciated

 

I don't understand why people post problems without identifying the engine, mileage, and any other useful information.

That said, Have you checked the fuel pressure?

 

Follow closely;
If the motor cranks and runs even a short time and will repeat again and again, keep some throttle on and see if it can be made to keep running on your foot throttle.
If yes, the IAC 'function' is faulty. This function is the only part that keeps the motor idling by providing bypass air the same as keeping your foot on the throttle..
.
If no, check fuel pressure for being way below 35 psi +/-.
If yes, repair the fuel system.
If yes, suspect the ignition switch of going open in the Run position when returning from the Crank position.
Some one has to put some common sense effort to find the failure.
Nothing wrong with the motor if it will start and run at all.
Good luck.

 

Thank you bluegrass, I will look into it and let you know.