Does your return line go all the way to the bottom of the tank and is there a strainer on it? I think somehow my return line is causing me to run out of fuel.
The return is routed back through the pump. Could his injection pump be leaking internally and causing his return line to become back pressured by the pump?
Pull your return manifold off and replace with clear hose routed to container. Same with the return manifold. It's likely your excess pressure is coming from the return side