fuel problem

I have a 01 mustang that sat for about 2 years and it starts strong and runs
for about 20 seconds then it bogs down  and dies even when giving it gas. i
scanned it and it throws a fpdm error and an intake error. After i looked up
the intake one it says from turning the ignition on and off a number of times
throws that code and the fpdm still show its off or not connected. i changed
out the fuel pump hoping it was just gummed up but it runs a little better but
not like it should. about to change out the fuel filter but would that solve it or
do you think its the fpdm. no wear and tear on the fpdm it looks new almost
and ive been told them going out are rare unless its damged or
submerged.