Filter in the tank may be getting clogged. Rig a vacuum gauge to the pump inlet using a hose set and tee. 

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Tyler Hardison
Sent: Friday, February 12, 2016 4:45 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Fuel Pump Noise

Aside from the normal startup sound, every once in awhile I hear a noise that sounds like cavitation noises? Like what I'd expect if there is air being introduced.. But I'm not smelling fuel, and there does not seem to be any visible fuel leaks.

Almost sounds like a broken piezo buzzer?

First question is, how long has it got..

Second question is, my van never had a "front" fuel filter.. (Not since I've owned it).. Maybe I should get one?

--t