96 Mercedes c220

I have a 1996 Mercedes c220. Received it in a
trade. It's in great shape on the outside and inside.
Not starting. The guy I got it from, said that he
was just driving it one day and it stalled. He waited
a little bit, turned it on, maybe went a few more
feet and then it stalled again and wouldn't turn on
again. He parked it, got another vehicle, and there
it stayed. 2 years. When I received it in the trade, I
went to go pick it up on a trailer, when I got to my
house... I hooked it up to the OBD, no codes
popped out. The guys seemed to think it was a
head gasket, so I verified that it wasn't, and I
continue to do some diagnosing... Which let me to
spraying starter fluid into the intake, and she tried
to turn on. Figured it was the fuel pump, so order
the correct pump and installed it, and now she's
not starting at all. Could bad gas allowed her not
to start at all? What other issue should I be
looking for? I hear the fuel pump when I turn the
key on... I hit it with a little bit of starting fluid, and
now it's not trying to turn on at all. Just turning
over. Thanks in advance guys