Newbie here.
77 f350, 4sp, 351m, 185k, dual tanks.
Replaced the fuel pump a couple of months ago and the new one ran fine till now.
It was acting strange for a couple days, idle dropping low when stopping as if out of fuel.
Not pumping, dry at carb., drips out of supply line when disconnected.
Activated aux valve, blew on supply line, clear back into tank.
Gas at valve connections.
Put hose into gas can hooked to pump, cranked engine, nothing.
Pulled pump, hand operated with supply line in gas can, get fuel to pump easily.
Reinstalled, no pumping.
Can see on the arm wear mark from contact.
What should I try next (electric pump?) Could the lobe be that worn?
Thanks

 

Can't say for certain if it's the problem with yours, but I had a 75 inline 6 on which the lobe was that worn it wouldn't pump but a dribble. Ended up installing an electric.

 

On a 351m the fuel pump eccentric is bolted to the camshaft timing gear, in my opinion it would be unlikely for it to wear out so much that it would cause trouble. I would try another pump. Also on my f150 the fuel line rotted out behind the main tank along the frame from all the mud that was packed in there. Good luck

 

Check the rubber fuel lines. With time and alcohol, they can get so soft the fuel pump suks them closed and no fuel flow. Happened to me. A few feet of new line and an hour or two fixes it.

 

With the pump off you could get a screw driver in there to see if the ecc. came loose, it has happened. You would have a 2 piece one so the outer shell spins. You put the feed hose off the pump into a can and tryed it ?