I've isolated the problem to something between the tank and pre heater. I was able to get the truck running this afternoon by using MWilson's advice and running a piece of 3/8" line from the steel line that goes to the heater into a 2 gallon can. I don't have time to drop the tank this evening so that will be tomorrows adventure. At this point I'm starting to like the idea of strapping a 5 gallon can to the hood.