On 8/25/2009 I had trouble starting 2000 f150 after it was warmed up.
I changed the fuel filter from advise I received from this web site.
All was good again till yesterday. It was in the 80"s and when I got it home,
it would not start. Turned over ok. It started this morning ok and seems to be working again. Is there some temp senser somewhere that it looks at that may not be working at times? Or should I try the fuel filter again? Any Ideas

 

What does it do when its not starting. Try to be descriptive. And what motor do you have. With how many miles and any recent issues other than the no starting.

 

It tries to start, will sputter and little. 5.4 and 47,000 on it.
No other troubles with truck. It has never had any other troubles at all.

 

When it does not start, can you hear the fuel pump running inside the gas tank. Be careful, the pump only runs for a few seconds after you turn the key, then shuts down

I could be that the fuel pump is going out on you. They can fail intermittantly

 

Should I hear the pump every time I turn the key on before I start it?

 

yes, you should hear a whine, whenever the key is turned forward, from the back of the truck.

 

I will listen to pump when working and compare when not working thanks.

 

It may be vapor lock?????

 

Vapor lock went away with carburetors.