Date:         Wed, 2 Feb 2005 14:40:01 -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 update

list:

an update on my pollution control valve fix. seemed to work well at first,
but, evidently, at high rpm, blow-by was sufficient to close down valve,
and this in turn caused pressure to rise in crankcase, thus in turn
causing oil level to rise in dip stick tube, leaking out all over the
place.

flapper valve in properly functioning black tower must simply open wider
and wider to some maximum with increasing blow-by. pollution control valve
in conventional application is different:  minimum flow at extreme
manifold vacuum, as in throttle almost closed at high rpm going downhill,
is shut tight in opposite direction if front fire to prevent explosion
inside engine, but allows maximum flow in between, at part throttle, i.e.,
at  moderate manifold vacuum.

in short, rather than opening farther and farther with blow-by, the
suggested pcv in series with black tower opens farther to a point, then
shuts down as blow-by increases still further, thus not properly venting
vapors to air intake. therefore, pcv really doesn't mimick action of
flapper valve in properly functioning black tower.

next try will be a restriction in hose - enough restriction to permit nice
idle, but not so much as to create excessive crankcase pressure = and no
pcv.

i wonder if failed black tower flapper valves have resulted in any engine
explosions due to front fires.

dan



On Sun, 5 Dec 2004 00:23:21 -0500, Daniel L. Katz <katzd54@YAHOO.COM>
wrote:

>chris:
>
>our '84 1.9 l had  similar symptoms . evidently, the black breather tower
>was running wide open, and too much air/blow-by was flowing into the air
>intake at idle (too lean mixture i suppose). a quick and dirty way to test
>this is to:
>
>1. pull beather hose off air intake and let hose vent into engine
>compartment.
>
>2. seal up now open intake inlet - duct tape works, rubber cap would be
>better.
>
>3. go for a drive and see if problem goes away, or at least is less
severe.
>
>i inserted a conventional PC valve into breather hose, reattached the
>breather hose to the air intake, and reset idle speed (with idle
>stabilizer bypassed) to solve the problem once and for all. $2.44 for PC
>valve vs $50 -$60 for new breather tower.
>
>hope this helps.
>
>dan
>
>
>
>
>
>On Sat, 4 Dec 2004 12:03:06 EST, JordanVw@AOL.COM wrote:
>
>>ive been having this strange intermittant problem with my '84 van for
some
>>time now..
>>i'll be driving along fine, then all the sudden if i dont have my foot on
>the
>>gas, the van will stall out..  no rough idle, no other warning..it will
>just
>>shut off..   i swapped the ECU and fuel pump relays (little identical
grey
>>relays in that black box) with eachother and that didnt do anything..   i
>>replaced a corroded ground strap from the head to the coil and that didnt
>help
>>either..
>>
>>no strange idle or warning lights precede these intermittant shutdowns..
>>anyone have any ideas?
>>
>>thanks
>>chris