Ok so I am new here and hoping I can get some help. me and my husband have a 2000 ford F150 4wheel drive with a 5.4 triton motor. About 2 months ago we went out to start it and it would turn over but stall out very quickly. A friend told me to try keeping foot on gas and brake and put it in gear,i did that and it stayed running. I then shut it off and it started up and stayed running with no problem. Well now it is has been doing it every morning this week. He has to start it and keep his foot on the gas pedal for around 10 to 15 minutes before it will stay running, and today after he left for work it stalled on him twice but starts right back as long as he pressing the gas. Any suggestions. My friend that told me what to do above said maybe an ignition relay?

 

There are several possible causes but what I can tell you is that a VERY common cause of this is a faulty Idle Air Control valve. That would be the first thing I would check or replace. Some say you can clean them. I've had limited success with that so I usually just replace them.
The IAC is what gives the engine enough air to continue to run at idle when the throttle plate is closed. And when they go bad, pressing down on the accelerator pedal illiminates the need for an IAC, so the engine runs. Not saying this is your problem for sure but I certainly have replaced a bunch of them for that exact same symptom.
Most parts stores sell them and if youll look on top of the motor toward the very back youll see it. Should be two bolts/screws holding it on.

 

Justin is correct. I'd also replace the IAC (idle air control) valve. It's not that expensive and saves you from doing the work twice. Located on the back of the intake on a 5.4l . Report back and let us know. Good Luck

 

If it was a problem with the ignition it wouldn't start.

I agree,
sounds like the IAC is clogged or bad.

 

its almsot 100% your IAC!!! i have a 98 f250 with the 5.4L in it an my truck was stalling out unless i had my foot on the gas, the IAC is a little tricky to get to, but worth the time doing it yourself!! hopeee this helpss..