Umm i am converting from carbs which ran perfectly at 4psi before like how i explained in the first post. I was asking if others also thought it must be an efi pump because it is Teed into the return line which is 1/4" which i would think would cause a restriction since the feed line is 5/16" and let the efi pump operate at 4psi. I dunno cos i havent pulled the tank out. Maybe it does have a low pressure pump in the tank but i dont have a reg and gauge.