2002 Ford Explorer Electrical fuel module

I have a 2002 Ford Explorer with just over 100,000 miles on it. My concern is this; one to two times a day the truck does not start. The battery is brand new, alternator checks out fine as well. We can hear the engine trying to turn over, the fuel is not getting to the engine. We have been to the dealer and the truck starts everytime of course, therefore no codes from the computer to report. (When you hear the high pitched sound right after turning the key, you know it will start) One mechanic tells us it's the the fuel pump, another mechanic says that it's the module under the dashboard on the passenger side of the vehicle. What is your take on this rather perplexing situation?