I installed a new Delphi fuel pump assembly, AC Delco fuel filter, and Delphi fuel pressure regulator this past Friday and now I have a buzzing sound that comes from the pump and travels up the fuel line to the fuel pressure regulator. The truck idles and accelerates fine with no hesitation what so ever. I had replaced the fuel pressure regulator in October with an Autozone one and it made the same sound with the old pump, but went away after driving from NC to AZ. Is it possible there is air in the system or is this a noise I have to live with? Thanks for any help in advance.