An infamous problem on the f150 is the fuel pump controller bolted to a chassis crossmember near the axle. The pot metal housing backside contacting the steel member corrodes badly from road salt, letting all sorts of dirty salty water directly onto the electronics inside. That buggers up the fuel pump, leading to a no-start.
I caught mine with a hole the size of a silver dollar, before the electronics started to fry. New ones come with a standoff so there's no contact between the metals anymore.
Maybe something similar on your 2000 'stang?
https://www.youtube.com/watch?v=HPbwBEfWVO0
Purging the fuel lines and swapping in a new fuel line filter afterward might be good too.
https://www.youtube.com/watch?v=smY3GNyRU4Y