Shutting Off
 

I have an 03 ranger 4x4 with a 4.0 the other day left for work pulled out and it just stopped running after a few minutes try got it to start back only to do it again I changed the fuel filter drove it same thing so put a fuel pump in it took it down the road ran fine last night then this morning pulled out and it just shut off again I’m at a loss any advice on my next step would be great

Welcome to the forum

What brand of fuel pump did you put in?
Unless it was a Motorcraft brand, "new" just means NEVER TESTED" not "it works"

So grain of salt on 3rd party fuel pumps, not uncommon for them to quit working within the first year, and they will replace them free, but just a pain to swap them out

With key on you should HEAR the fuel pump run for 2 seconds, its not quiet, a HUMMMM from just behind the cab for 2 seconds
Repeat key off and on as much as needed so you KNOW what it should sound like, fuel pump will run for those 2 seconds EACH TIME key is turned on

So that's the fuel part

Electrically their isn't much that can shut down a running engine, the ignition switch of course, but gauges and dash lights would all turn off if that was the case, and you don't mention that
The Crank sensor failing can cause it but there wouldn't be a restart possible in most cases
That's the only sensor that can stall a running engine

There are controls like the IAC Valve that the computer uses to set idle, if its failing then engine could stall but ONLY at idle, not while driving

The thing about an intermittent issue is that there is no way to diagnose it, even if it happens when trying to diagnose it, lol

There may be trouble codes in memory, CEL(check engine light) doesn't need to be on
If you don't have a code reader yet I would get one

You can get a Bluetooth OBD2 reader that works for any vehicle 1996 and up, so not a Ford thing, for under $20
They work with FREE APPs on your smartphone
This allows you to read codes, but ALSO you can watch Live Data with engine running and maybe catch something if watching when engine stalls

If there are no codes then its most likely not an electrical issue unless its the computer itself...................but you are not there yet, lol
A mechanical issue is usually fuel supply as you originally guessed, Rangers never had fuel pressure sensors
A clogged exhaust can stall an engine but its a slow stall as pressure builds up, loss of power then a stall, not a sudden stall