fuel problem

[area51js1]

I am having a fuel problem...again. I replaced the low pressure pump in the tank and everything was working fine for a while, but now it won't start. If I prime with starter fluid, it starts but will barely idle (really low rpm) although if I slowly give it gas, I can bring the rpms up and it will continue to run as long as I give it gas. Fuel pressure is 40 - 41 psi and holds steady but when I turn the key on and the high pressure pump kicks in, it never shuts off even after the pressure stabilizes at 41 psi. Anybody have any ideas?

 

[area51js1]

I've been racking my brain over this and I keep going around in circles. It doesn't make sense that the fuel pump would keep pumping once the pressure has stabilized. It only takes a few seconds after turning the key on for the pressure to reach 40 psi so why won't the pump shut off? Do any of you know if the fuel pressure regulator is involved with shutting off the high pressure fuel pump? The pressure doesn't drop over time and when I pull the vacuum line off of the fpr, no gas dribbles out so it acts like it's working fine. I don't see an electrical connection to it so I can't imagine how it would be involved with shutting off the fuel pump but I don't know how the pump would "know" to shut off without sensing the fuel pressure. Could it be "something" with the relay that keeps the pump on? Does anybody know what the feedback mechanisms are for the fuel pumps? Finally, (and this is the real kick in the pants) if the fuel gets all the way to the fuel rails at 40 psi what possible reasons are there for it not to start unless I prime with starter fluid?

 

[Jorley]

What year, engine and model. It would help to have this info.

 

[area51js1]

Of course...sorry about that. It is a 1986 Bronco II with a 2.9L.