96 Neon random stalls on hills, no codes found.

I have a 1996 Plymouth Neon with about 73k miles on it. About a month and a
half ago, the original 96 fuel pump died with no warning and had to be
replaced. About a week ago my engine started to be cutting out randomly
whenever I go up a hill. I was able to replicate this 6 times before
taking it to the dealer service dept, the same folks who replaced my fuel
pump. However, they claim they could not get it to stall on thier hill
tests and turned it back to me at no charge. For the next few days my car
ran like a champ, but now I was able to get it to stall on the same hill
that was giving me issues before. Here's what happens. When going up a
hill about 1/2 way up the engine feels like it is cutting out, sort of
like it's going into neutral. If I floor it, the engine kicks back in,
revs at a high RPM as it should as I've just floored the accelerator. If
I'm still on the hill the engine may/may not cut out again and I'll floor
it, and repeat the proccess until I reach the top. Downhill, and flat
roads the car runs fine. The idle is fine as well. Only once did it fully
die on a hill right outside my apartment as I started up the hill from a
standstill. After letting it rest on the hill incline for about 1 minute,
the engine fired right up and I was on my way with no other problems. I'm
guessing its something with the fuel pump or fuel delivery system. But
it's still very random at this point, for me to be able to really pinpoint
something. Any help would be greatly appreciated as this problem is getting
on my nerves.

 

Since the trouble seemed to start after the fuel pump was replaced, it
is possible the pump or pump feed came out of position in the tank
(improper installation?) and when you go up the hill you are changing
the angle of the gas tank and possibly shifting the fuel away from the
feed. (happened to me, pump came loose.) Joe