Help please! 2003 Ford Crown Victoria wont start!

My 2003 crown Victoria will randomly not start. By not starting, I mean that I have power to lights, windows, etc and when I turn the key it goes on temporarily, for about 1-2 seconds, and then shuts off. If I crank the engine and hold the accelerator giving a steady amount of gas the car will stay on but once I remove the gas it shuts off. This has happened about 4 times now and every time it has happened I just let it sit with the key out for about 10-15 minutes and the car starts up no problem. Any ideas what could be wrong? The car has a new alternator and the battery was checked and is at 100%. Thanks in advance for your time.

The problem is most likely with the Idle Air Control valve.

https://www.rockauto.com/en/catalog/ford,2003,crown+victoria,4.6l+v8,1410567,fuel+&+air,idle+air+control+(iac)+valve,6072

The IAC valve allows the engine to idle anytime the accelerator pedal is released.

One way to determine if there’s a problem with the IAC valve is, the engine doesn’t stall as long as the accelerator pedal is depressed.

Tester

If that was the issue would the car normally start most of the time? I am able to start the car 100+ times before i have this issue happen. Also, how do I test if the IAC is bad? You say make sure the pedal is depressed and if it does not stall then it should be okay?

Locate the IAC valve on the throttle body.

Start the engine and let it warm up.

Take the handle of a screwdriver and rap on the IAC valve.

If the engine idle speed changes, replace the IAC valve.

Tester

Ok thank you. I will try this out soon and get back to you

Checking fuel pressure while in failure mode will rule out a bad pump. My experience for whatever reason with fords of this era, pumps fail while the engine is hot, let it cool and starts right up.