If you installed a new sender unit that has the fuel line connection, then the sock filter inside the tank is a plastic screen that will collapse, creating a no- fuel condition. Mine did. I replaced that sock with a stainless screen that was reinforced with a stainless coil to prevent collapse. Problem solved. I was 150 miles from home on the "Shake-down cruise" when it happened. New tank, new sender, rebuilt glass bowl pump, new lines, freshly rebuilt carb. Finally blew back through the line to the tank and flow resumed. Did it again a few days later. That's when I replaced that crummy sock.