2000 Ford F150 fuel pressure issue

Hello, thanks for reading my question,

I have recently acquired this truck in a cranks but
wont start condition. It was not making pressure at
the rail. Unfortunately I have been replacing parts
probably unnecessary like the fuel pump, filter, and
regulator. The truck has 142,000 miles so those
parts may have been worn anyways, so Im not
terribly upset about that. My fuel pump runs and
creates pressure while its running, and sprays out
of the schrader valve like crazy when its priming
when i tried it. The problem is it loses pressure
IMMEDIATELY after. So after checking my oil and
finding it smelled like gas, I now believe its a stuck
open injector. I pulled the fuel rail, zip tied the
injectors to it so they didnt pop out, and cycled the
key. None were leaking. I now check pressure, and
have it!!! I put everything back together and tried to
start it. It started for a second and died, checked
fuel pressure now, and back to nothing. So I now
feel that something is wrong with the electric going
to injectors, and making them stick open. I have an
electric meter, but where do I start? Does it sound
like I am on the correct avenue? Or am I
overlooking anything.

Thank you very much for reading