Diesels don't like any air in the Fuel lines, and a leak will allow air in.
If you can fill the Pump with fuel and it runs until dry, what is your Clear Line Showing?.
As the Pumps get weak, and won't draw any fuel that is a issue too and they usually have to be rebuilt or you can add a "helper" pump to draw the fuel out of the tank.
If your tank's Sump or Swirl pot is broken or the Tanks inlet filter screen is Dirty that is also a issue with Fuel delivery as there is a screen inside the tank that can get plugged and stop fuel from flowing to the pump.
So if you take a 2 liter bottle and place fuel in it and allow the engine to draw fuel from it and it runs till empty, then you are looking at a Bad Filter or Tank issue ....Or a weak injection pump.
If you have taken off your "Banjo" fittings and either didn't re-condition the seals or replace them then they will leak.
To re-condition them you sand the burr's down and make them Shiney.... Hold them over a flame until they change to a dull color. They then should be good to go. My Local Napa, and a few injection pump rebuilders have them.
There are 2 sizes, I can't remember the diameters, but using the etka you can find the PN and go from there. http://www.oemepc.com/
So you have possibly 2 issues, a leak and possibly a clogged inlet.
Get the Leak fixed first as that will tell you more about the delivery issue.