Fuel Pump.
There is an extended warranty for the fuel pump to 10 years. Ford will
replace the fuel pump for free once, that's right 1 time if the fuel module
is bad.

I have this problem with the focus not starting. It will start first
thing in the morning, but i can drive and stop some were and the car
might not start again. I put a new battery in it about 3 months ago. I
have had the battery and alternator and starter all checked, they were
fine. I have had to replace the starter relay once, it was bad. It
seems like if it sits awhile, sometimes hours, it will start. Anybody
have the same problem or solution, I would certainly be grateful.
Thanks.