Yeah I guess I was envisioning the injection pump pulling the fuel from the jug but what he was probably meaning was insert the line from the factory mechanical lift pump.Bob, I think the Air Dog fuel pump will make that testing method difficult. Not sure if an in bed transfer tank has a vented cap or not. You may have hit on an issue there. The word "transfer" indicates it's not designed as a primary fuel tank. Did you add a return line to it? If so, how far into the tank does that line go. Might crack the cap open and see if your problem changes.
I do have the return line routed to the tank. It is just connected to a barbed fitting in the top of the tank that dumps into the tank from the top. The supply is connected to a draw straw in the tank as per a typical Airdog installation. I will definitely be checking the possibility of a venting issue with the tank. What would the issue be if it is not vented correctly? Air lock I’d guess? It’s clearly still flowing but maybe preventing it from flowing well enough to keep up with supply? With the draw straw submerged constantly, it would have to be on the return end I would think?