well, this is one i've never heard of before. i have a '66 F100, bone stock. it sat for over 9 years, but started on the very first crank when plied with fuel. the previous owner told me it'll need a fuel pump because this truck "seems to eat fuel pumps". no problem, i'll replace it and it'll be fine. i bought a new mechanical pump, cranked it over....nothing. plenty of fuel in the tank, but nothing to the (newly rebuilt) carb. i determined, along with another opinion that the eccentric was probably bad and i'd just move to an electric fuel pump. i did. edelbrock 4 - 7 psi ( i forget the model number) electric pump, filter, guage and regulator. i wired it thru a relay and off it went, running as it should. it worked for about an hour while i fettled with the carb and other things. then, it just stopped pumping fuel. it still runs, but it's just not moving fuel. i figured it must be out of gas so i put another 5 gallons in it. nothing. i returned the pump to summit for replacement, installed it just like the other one. it ran perfectly for about an hour and now IT won't move any fuel. it still runs when the key is turned, but no fuel movement. before anyone asks, yes i DID blow out all lines (forward and backward) as well as removed the tank and cleaned it. the tank was stored empty and didn't have as much as a thimble full of dirt in it.
does anyone have any suggestions? i cannot believe that i got two bad pumps from edelbrock. and....why did they work initially but stopped pumping while still running.
one minor thing, i installed the pump on the inner frame rail under the drivers seat. it is ever so slightly tilted with the outlet being higher than the inlet. maybe 1/16" if that. should it be tilted the other way? does it make a difference? please help!!!

 

Is the filter clean?
Do you have a vented gas cap? Try it with no gas cap.
If you disconnect the fuel line from the inlet side of the pump does fuel run out. If it is primed with no air in the line, it should siphon out of the tank. If not, the pickup tube may have pin holes in it.
Those little pumps are sensitive to running dry or being forced to pull too hard and will give up.

 

the filter came with the pump so its brand new. the gas cap is vented because its a locking cap but fits SO loose that its essentially a vented cap. definitely no issue there. im absolutely sure there are no pinholes in the pickup line only because of the pristine condition of the inside of the tank. i've put eyes on the tube when i was cleaning out the tank (which was spotless inside).

im gonna disconnect the inlet side and see if it runs. i also want to pull the pump off, run it and see if it pulls fluid from a bucket.

 

If that pump ran for an hour that is plenty of time to plug that little filter. Take it off and blow thru it, if it's plugged you will know..

 

i just had a thought. it's possible that the connection between the inlet line to the tank (on the topside) and the line INSIDE of the tank is not completely without an air gap. that gap might break any suction that the pump is pulling. what i'll do is take off the line, reconnect it and see if it pumps again.
full disclosure....after i installed this second electric pump, it didn't pull any fuel initially. i realized that, at some point, i HAD disconnected that line after removing that first pump. i connected it, and the pump worked perfectly for an hour or so.
at some point i'm going to install a new tank under the bed and be done with the in cab tank.
p.s.....my wife thinks i should just put a new motor in it.

 

p.s.....my wife thinks i should just put a new motor in it.
Lucky man! Not many of them think like that.

 

ok....the mystery she is a solved. the line into the tank was not secure as were 2 connections. it was a sloppy oversight by me. it's all up and running.
BUT......i have a new problem. i'll start another thread regarding it. the truck won't run unless on choke.

 

Dude, strike while the iron is hot! Get that crate motor on order NOW!

 

lol....i just don't have the coin right now. but i'm keeping that fire smoldering for when the time comes.