In my case it was crud in the gas tank.
If replacing your fuel filter does not do it, try removing the tank (quite
easy) and do a few cycles of: pour gas / shake / empty.

At 02:08 PM 06/08/2001, Steve Cotsford wrote:
>Try replacing the fuel filter.
>The pump might just be working too hard to suck the fuel through it.
>This sound is known as cavitation.
>
>Good luck,    Steve