Hello, my Vulcan starts to misfire at 2500 rpm. Thought it was the fuel pump, so replaced it from quantum fuel systems. Still had issue replaced spark plugs, air filter and even the hoses. Got it diagnosed. They said,The bike starts at 40 psi that slowly bleeds off. They suggest to replace the fuel pump so I called quantum getting a new one, however, does anyone have any other ideas? Could it be something other than the fuel pump. Are there sensors that can go bad if so which ones typically do and why. Thanks.