Date: Wed, 6 Oct 2010 14:26:33 -0700
Reply-To: Old Volks Home <oldvolkshome@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Old Volks Home <oldvolkshome@GMAIL.COM>
Subject: Re: Fuel Filters vs Fuel Strainers
In-Reply-To: <4CACDB58.7040909@charter.net>
Content-Type: text/plain; charset=ISO-8859-1
The Square "Pre-Filter" is just that - a FILTER, not a strainer as you would
be led to believe by that Digifant Book. VW 133 133 511. This was used as
the ONLY filter on 75-79 Fuel Injection L-Jet engines on Beetles and Buses.
In a difference of opinion with Scott, a Pre-Filter and the downstream
Cannister Filter was used on 82-later Air 2.0 & Water Boxer 1.9 engines
through at least 85, particularly on the California Models. I know because
I have owned both in the past 18 years. Only an 80 2.0 I once owned just had
the plastic Square Filter. And I continue to run both on both my 84 GL and
84 Westy as they originally came with.
VW did away with the Pre Filter on the Digifants because the Fuel Pumps of
the era and replacements since then have a screen mesh inside the Fuel Pump
Inlet. Not really comfortable with the adequacy of that, so I would run a
Pre Filter anyway if I had a choice.
My nickel's worth and YMMV
--
Jim Thompson
84 GL 1.9 "Gloria"
84 Westfalia 2.1 "Ole Putt"
72 411 Station Wagon "Pug"
75 914 1.8 "Nancy"
Full Timing Since March 1999
oldvolkshome@gmail.com
http://www.oldvolkshome.com
***********************************
On Wed, Oct 6, 2010 at 1:26 PM, John Rodgers <inua@charter.net> wrote:
> In working with my two vans that were stored for 10 years, I have had
> to deal with many issues. One was getting the fuel delivery system
> working again. This included opening it up, and flushing all the old
> fuel and junk from it. The injectors were frozen and would not work, so
> had to send them out for servicing. They work fine now. And the fuel
> pump on my Carat was seized so that had to be dealt with. By removing
> the pump, and spraying carburetor cleaner into it and allowing it to sit
> over night, then repeating the process, the pump freed up and now works
> just fine.Then there was the issue of the fuel filters.
>
> In as much as I'm having idling problems, I got out the Digifant Fuel
> Injection System manual to study. I found interesting remarks concerning
> the fuel filters. In as much as there has been a good bit of talk on
> this list about the large filter after the pump, and the small filter in
> front of the pump - here is what the book has to say about them.
>
> ************************
>
> *Fuel Filters*
>
> Two types of filters are used on the Digifant system.
>
> One is a square _*plastic fuel strainer*_ which is mounted before the
> fuel pump *_to __protect the pump_* from foreign particles.
>
> The *_main fuel filter_* is a metal cylinder which mounts behind the
> fuel pump. *_It has a finer filtering mesh to protect the fuel injection
> components._*
>
> Both are lifetime filters and do not require replacement under normal
> circumstances.
>
> *********************
>
> Of interest to me is the different function of the two filters - the
> first to protect the pump. the second to protect the FI components, ie,
> the injectors.
>
> I note that one is a fuel STRAINER, while the other is a fuel FILTER.
> Quite a different between a strainer and a filter.
>
> I have read that the square strainer can be left out, but after reading
> this - I would not. Each filter/strainer serves a different and distinct
> purpose and therefore both need to be in the fuel system..
>
> Just my $0.02.
>
> John
>
> --
> John Rodgers
> Clayartist and Moldmaker
> 88'GL VW Bus Driver
> Chelsea, AL
> Http://www.moldhaus.com <http://www.moldhaus.com/>
>
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