fuel problem??

[guardian1]

i currently have a problem with my 90 f150 with 300 i6 (automatic,e4od transmission). it will only want to run when i directly induce gas in my air ports on my throttly body. i have already dropped and cleaned both tanks and rebuilt both fuel pumps also have replaced fuel filter and performed complete tune up. the tps checked fine aswell as the egr. the entire problem is as stated it will only run for a few minutes when i directly induce gas through air induction on throttle body. could this be a mapp sensor gone bad or the iac? i do know that the gas is making it atleast to the injectors. any help would be greatly appreciated for i am out of work now and this is my only means of transportation to find more work. thank you in advanced

[Conanski]

Do the fuel pumps cycle for a second and then shutoff when the key is first turned to run? Or do the pumps run constantly as long as the key is on?

What is the fuel pressure at the rail?
Any codes present?

[guardian1]

pumps do cycle then shut off but they have always worked in this manor, i can hear them from in the cab. fuel press. at rails i have no idea what it is, would be wise for me to check, need guage though. cant read codes, have a snap-on computer but last time i plugged into this truck it shorted my computer, something is crossed on the wiring. i have had truck for ten years and this is my first main problem out of it with 417,000 miles logged.

[guardian1]

where is the port to screw the fuel pressure guage into at? i cant find one here.

[brett12396f150]

Its on the way back of the fuel rail, its a real b**** to get on, i had to use an extender to make it easier. If you feel the fuel rail its after the intake, its a scharder vavle Easy way to see if you have fuel pressure at all is to stick like a pen cap into the valve, see if fuel squirts out...(try after attempting to start to build up pressure also) if not you have no fuel at all.