Fuel pump bubbles can cause problems and a bad fuel line between the tank
and pump can suck air into the pump & cause bubbles especially if the inlet
screen is a little clogged.

I discovered this one with my 1972 Mercedes 380 SEL 4.5. The line did not
leak a bit but the vacuum pulled air in through the hardened & cracked cloth
covered fuel line!

The fuel line I pried & pulled off was so hard that it retained its exact
shape once removed and a new piece of line solved my problem.

Tom
www.towercooler.com

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM] On Behalf Of
Ken Lewis
Sent: Thursday, July 15, 2010 9:05 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: fuel pump producing bubbles

Sam,
I'm stumped  A google search revealed "insufficient fuel" as a possible
cause. Said to check for holes in fuel line on inlet side of pump. Let us
know what you find out. .
Ken Lewis
http://neksiwel.20m.com/
in statu viae

----- Original Message -----
From: "Sam Payne" <bungeegull@HOTMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Thursday, July 15, 2010 5:19 PM
Subject: Re: [VANAGON] fuel pump producing bubbles

> The injectors were cleaned recently, and have only seen about 3,000
> miles since. Also, the fuel pressure with the pump running tests dead
> on, and the residual pressure stays up for long enough.
>    I haven't tried disconnecting the O2 sensor, and will. Thanks for
> the suggestion.
>     But why the bubbles?
>
>        thanks, Sam
>