Hey guys thanks for the help on my earlier post last week. Im still having a a gas problem though.
Heres the situation, I have an 86 f250 460 with elec fuel pumps. Which ive now had running but no more than 30 seconds. Ill walk ya through what im doing to get it running and whats shutting it off.

The carb is out of fuel so i turn the engine over a few times walk around open the flap on the carb push the throttle and make sure gas is going in. When i have enough gas i go turn the engine over it fires up and runs, wont idle but i hold it at about 1500 rpms, and after 20-30 seconds it runs out of gas. When it runs out of gas ive pulled the fuel line off the carb to check for pressure im thinking if there is any pressure gas should run out but none runs out its bone dry maybe 1-2 tiny drops.

Im not really sure where to go from here. It seems to me my fuel pump is shutting off.
Thanks for any help guys

 

crank it with the fuel line off and see if you get fuel

 

i had the exact same problem with my efi 302, and it was the fuel pump, it would take a few key turns to start, run for 30sec or so then die, and i got fuel all through the rail, but in the end it was the pump

 

You should be able to hear the pumps running with the key on, you dont even have to crank it.

Here is a list of thing it could be:

clogged fuel filter (its located in the inlet to the carb, a little gold thing).

clogged return fuel valve (if you have return lines).

clogged or bad duel tank switching valve (if you have duel tanks).

clogged in tank strainer (filter) or dead fuel pump or both.

fuel pump relay, and a fuel pump cut-off relay (this is how i label them atleast) fuel pump relay supplies power to the pumps, but passes threw the fuel pump cut-off relay first. The cut-off relay checks oil pressure and will cut-off power to the pump if there is none (to save the engine). They are located on the drivers side under the master cylinder. If the relays seem ok, it could be the oil pressure sender has gone bad. there are 2 of them, one is for the gauge on the dash, and the other is for the cut-off relay. both are located behind the carb (way back there) the one for the gauge has 1 wire to it, the other 2 wires. the one with 2 wires is the one that may be bad (to test this you can pull the wires and jump them together. with the key turned to the on position you should hear clicking from the relays). if its the oil pressure sender the pumps will still pump gas while cranking/starting the truck, then the power supplies switches over to the cut-off relay, and it will stall soon after.

also could just be a bad wire

 

very specific and gold star for you! mine was the pump but it still made the whinning noise when you turned the key

 

yeah i take the line off the carb after the return valve and good fuel when cranking and pulled the set screw above the in carb filter and good fuel when cranking. its just that the pump seems to shut off after a bit wasnt sure if its electrical or the pump

 

I would try giving the pump straight power from the battery to isolate it from everything else in line. If it still shuts off in 30 sec, then it is probably the pump. Does this happen with both pumps? I would also check and grounds to make sure they have a good contact.

 

I didnt get a chance to work on it today, Im gonna tear into it tommorw. With the key on i dont get any fuel out of the lines but when i crank the engine over i get fuel out of the lines. Engine runs for 30 seconds or so like i said and then shuts down and the carb is sucked dry and there doesnt seem to be any pressure.

To anwser bghnkinf250 I have 2 tanks but the truck has sat for 10 years and the other pump doesnt give me any gas at all. So im gonna replace the one that isnt working at all and if i run fine off that tank then i know the back fuel pump is also bad.

Ill let you guys know tommorw night if problem is solved or not. Incase someone else runs into this.
thanks for the help

 

Well Ive dropped my tanks and what a rust pool. After looking Inside the tanks ive got a couple new ones on the way should be here tuesday but ive run into another problem. The whole assembly that drops into the tank is rusty on both tanks as well. The front tank wasnt a problem to find a replacment. But the back tank no one in my town seems to know where to find one. The Ford dealership was closed so hopefully they will be able to get me one on monday. if not is there any other places you guys go for parts?

 

is this what u are lookin for?

http://www.lmctruck.com/icatalog/fd/full.aspx?Page=115

 

Ok guys Ive replaced the fuel tanks / pumps and sending units (front one isnt on yet No voltage at that connector) after i took the old pumps off i hooked them to 12v and listend to them, front didnt run, and my back one wasnt healthy. So replacing them needed to be done but. I still having a fuel problem.

Ive checked out the wire diagram for most 460 engines that i found in horsepullers tech tips. If im reading it right there is a bypass off the solenoid when you start the engine. What seems to be happening to me is when im cranking the engine i have Power to the pump. But as soon as i Let off and its just on run there is no power and after 30 seconds the gas in the line is drained. Which part would be causing this to happen ?

Edited part
Ok im pretty sure its the relay or the nuetral saftey switch. Fuseable links are good. and everything past the dash works otherwise the starter bipass wouldnt work. how does a guy test the relay.