Fuel pressure dropping while driving and under acceleration to zero at idle runs 4 lb electric Blue

Since I have installed a supercharger I have it ran it with any boost due to the fact that it's 30 over and running over 10 and a half to one compression. I have just been driving at normal which doesn't make any boost until it's under a load. It's been a long project. Have tried different things but it started out with a single four barrel. I'm in the process of building a stroked 440 which will be set up to run boost and hopefully I will have the fuel issue resolve before I get the other one put together