Hi I'm new my 86 ford f150 v8, so new I'm not to sure of the size of the engine. But, I'm getting real familiar with the fuel system. The truck runs pretty good down hill, however when going up a hill it is having trouble.( just a lack of power) Being new to me I wasn't sure about the gas millage, so I filled it up often. It seemed like it was getting great mpg. My dad also drove it and I thought he must have put fuel in it. That is how I ran her out of gas. I've put less than 250 miles on the truck. Maybe it is operator error, but the truck wasn't taking fuel from the pump. After the tow when troubleshooting I knocked on the tank and to my surprise it was empty. I bought fuel and put in in the tank via a gas can with little effort. With the lack of power in mind I bought a new fuel pump and checked the fuel system from the in the tank pump to past the fuel filter at every junction. I needed to bleed the fuel system of pressure from the start, i depressed the schrader valve and some fuel came out, I disconnected the fuel line past the fuel filter. After replacing the fuel pump I checked the new pump, it worked great shooting fuel (the replaced pump received a similar check while mounted, the fuel came out but it didn't shoot out)
That is the back story.
Can anyone help me with figuring out why I am not getting fuel to the rail.

 

do you have dual tanks?

 

Yes

 

Do you have the fuel pressure operated tank select valve / reservoir. Looks like this:
http://i608.photobucket.com/albums/t...ordfuelres.jpg

These things are problematic.

There is a fuel filter in the bottom. You just unscrew the bottom housing to replace it. Note the main fuel filter is as different part located in front of the high pressure pump.

If that selector valve and/or the in tank fuel pump(s) are not working then strange things happen such as fuel from the EFI fuel return line being sent to the wrong tank in some cases overflowing the other tank. BOTH in tank pumps must be operational in order for the valve to work correctly.
If for whatever reason fuel is not being pumped by the tank pump(s) then the engine will still run. In my case the engine would start to cut out and buck at speeds over ~50 mph. The high pressure pump also give a noticeable whine when struggling to get enough fuel to pump.

I ended up replacing my tank selector with an electric motor driven tank valve.
Do a forum search for duel tank or search on my username. I have extensive info posted on troubleshooting the duel tank system.

Another thing to check is the fuel pressure regulator on the fuel rail.

 

I agree with klricks on this one. I have a 1986 F-150 with dual tanks and that selector valve on the framerail under the drivers side door. I have had to replace it before. It is a dealer only part and it's about $170.00.

 

Thank you for the advice. I'll keep trying,

 

Do you know if I can put fuel in the fuel rail through the schrader valve. Maybe just using gravity as pressure. Might that cause more harm than good?

 

Could I introduce a vacuum to the fuel rail to draw the fuel in? Might that do more harm than good?

 

To check the fuel tank select can I just route the supply and return around it, as a way to check if it is the problem before making the expense of getting a new one, or is it key to the fuel system somehow?

 

I think if you try to introduce anything into the system by the way of the schrader valve you may set yourself up for a vacuum lock issue. Also the valve that we are speaking of is essential in a two tank system. because of the fact that it's function is to regulate fuel flow from either tank. I have been told that there is a filter in the bottom of this valve. You may want to check into that as well?