wryork25

I have a 1990 f150 5.0 4x4. I hae replaced the fuel pump, dizy and plugs. The truck did not start when I bought it. It will turn over with starter fluid in the TB. Once that is gone it cuts out. I just recently got my hands on a gauge to tell what the fuel pressure is at the rail. I know that fuel is getting to the rail but I am going to check that it is the right pressure tonight. My question is, if the fuel pressure is right and it holds pressure what else is could I be missing. The only other thing that I can think is that maybe a injector is stuck open.

flareside_thunder

You need air, fuel and spark. One of those is not getting where it needs to. For giggles, look on the driverside firewall in the cab and make sure the inertia switch hasn't been tripped. If it hasn't, make sure you're getting fuel at the rail. If you're still not....I'd be swapping the fuel pump relay.

Scraptor

Sounds like a relay , related problem check out the link. https://www.f150forum.com/f10/new-pr...roblem-151856/

wryork25

So I checked the fuel pressure tonight. I am getting about 10 psi when I turn the key to just before run. When I crank the motor over the fuel pressure comes up to 37 psi. The motor just cranks and cranks. It will kick over if I spray starter fluid in it. When I stop cranking it over the fuel pressure does stay up and continued to stay up for as long as I was out there (15 min or so). So what next, I am lost.

wryork25

Scraptor both of my relays come on could they still be bad

flareside_thunder

The relays should be fine since you're getting fuel to the rail. 37 psi is good. Does it try and kick over with the gas pedal floored?

wryork25

No it does not try and kick over with the gas pedal to the floor. I have checked a couple of the injector connectors with a noid light and I am getting the pwer signal to them. It is like I am not getting any fuel in the clynders.

wryork25

Does any one have any suggestions..... I am out of ideas here.

Ol' Navy

Will your truck run as long as you have your foot on the gas pedal?

wryork25

no the truck will not run at all. The only way that I can keep it running is if I continously spray starter fluid in the throttle body. once that fluid is gone she dies.