Date:         Mon, 6 Dec 2004 04:07:24 -0500
Reply-To:     "Daniel L. Katz" <katzd54@YAHOO.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         "Daniel L. Katz" <katzd54@YAHOO.COM>
Subject:      Re: strange cut off problem with wbx vanagon

list:

as a follow up to my last post, after a couple of e-mail queries:

the black breather tower is more or less like a PC valve, even though the
engine doesn't have, so far as i know, a conventional positive crankcase
ventilation system. nevertheless, the black tower does vent blow-by and
crankcase vapors into the air intake, where they become part of the fuel-
air mixture.

i bought an inexpensive PC valve at wal-mart for $2.44 and inserted it
into the air intake port, and then slipped the breather hose over it and
onto the inlet pipe. the side of the PC valve that would go into the valve
cover on a conventional car faces the breather tower (this is the inlet
side of the PC valve), and the side that would be connected to a vacuum
hose is just inside the air intake (this is the exaust side of the PC
valve). the PC valve is a lose fit, but the shape of the housing is such
that it can't slip or get pushed into the air intake. the entire job took
less than 5 minutes, and was done with my hands only. the pressure
difference across the PC valve will tend to keep it in place, although i
suppose i really could have inserted it anywhere in the breather hose,
which is snug over the widest part of the PC valve (but not so tight as to
stress the hose). i may look for a slightly bigger diameter PC valve to
provide a snugger fit in the air intake, and possibly relocate the PC at
the breather tower.

prior to this fix, i too had the problem of the engine konking out unless
my foot was on the gas, but now it idles again like a champ. finally, in
the event of a front fire, the PC valve will close tight and stop the
flame front from travelling into the crank case, which could cause a
serious explosion.

my guess is that rubber parts eventually disintegrated in the breather
tower, and it is effectively little more than an open pipe, without much
ability to modulate the flow of blow-by and vapors, or stop the flame
front from a front fire.

i've never taken a breather tower apart, but there are some past posts
that at least give an idea of what is inside.

hope this helps.

dan