I know there is supposed to be a "whine" coming from the fuel pump but sometimes the noise is really loud or really quiet. It gets loud or quiet all different times, I can never make it loud or quiet. Why is that the sound level never stays the same?

 

the longer its running and the hotter it gets, it louder it will be.

 

I believe the 255 has 2 stages that it runs at? Anyone clarify this. Mine does the same.

 

Thats true, sometimes its the exact opposite. I start the car and the fuel pump is really loud and after driving it gets quiet. It is never the same day to day.

 

How low do you run the tank on a regular basis? I used to run my til the light came on alot. Mine started to do the same thing for a few months then I went to fill up the tank one day and the car wouldn't start. I had to replace the pump. Now i fiil up when I hit 1/4 tank. May not have been the cause but just making sure.

 

Everytime it gets down to a 1/4 tank sometimes when its at a 1/2 tank.

 

at least your not letting it run too low.