94 4.6 has no power mid-wot

[AKWE-gt]

my buddy asked me to work on his 94 cv the symtoms are hard cold starts and no power from mid-wot. i just changed the spark plugs, wires, and fuel filter. the engine has no problems starting when warmed up , has good idle and has good power from idle-mid throttle. the only thing that looked a little suspicious was the spark plugs from the left bank. the plugs had more carbon build up than on the right bank. the tune-up helped a bit but the problem is still there. oh yeah, there is no code being flashed or stored either.

[ModMech]

Fuel pressure

[AKWE-gt]

i don't have a fuel pressure tester but is there a particular part i should be concerned about like maybe the regulator or a weak pump.

[ModMech]

Sound like it might be a weak pump/restricted filter etc. Lack of pressure anyway.

[AKWE-gt]

alright i'll check it out,thanks.