Hello, The inertia switch plunger is supposed to be down right? I was working on the lambda counter last week which is right next to it and possibly have bumped it. The huming I heard isnt the fuel pump. I disconected the wires to it and still heard the huming. So it looks like I have something wrong with the wiring to the pump. any ideas? all the relay updates have been done to my car:) Thanks for the reply, that was very nice of you to take the time David #2496