1999 Mitsubishi Eclipse GS non-turbo randomly stalls, wont start back up.

I was driving on the interstate going approx.
70mph and it randomly died. No stuttering,
nothing. It wouldn't start back up. Had it
towed home and my father looked at it. We
thought it was the fuel pump, it's getting
spark, I dont think it's an air problem, but
instead a fuel problem. So we got a fuel
pump but still the same problem. It doesn't
want to start but when it does it stays
running from 2 seconds to like 20 minutes
and stalls. When it doesn't start, my father
sprays a little starter fluid into the air intake
and it fires right up. We're thinking maybe
fuel pressure regulator but we can't seem
to find that on my car nor anywhere on
Google. What do you think it could be? Also
where can I find the FPR at on my car?