I have a truck with some problems.Ford F-150 1993 6 cylinder
fuel injected

here`s what`s up

I switch to rear fuel tank when motor running,motor dies,switch back to front tank,it runs fine.
Sometimes if I jump in it and go it dies when I give it a little pedal.I usually leave it sitting for a half hour or so and it starts.
I put a fuel pressure tester on it and when running on front tank,45 lbs of pressure.I switch to rear tank and it slowly falls until motor dies.
I let the pressure off and turn on the key,hear the pump activate,and the pressure is 45 lbs on both tanks.

I am not sure where to go from here.I am going to change the filter since I have a new one.

tks

 

I retook the fuel presure and here are the results
key on,engine off front tank 38 psi
key on,motor running front tank 46 psi
turn engine off and pressure went to 54 psi(front tank)

key on engine off rear tank 56 psi