Date: Wed, 26 Sep 2007 17:40:11 -0700
Reply-To: "Mike \"Rocket J Squirrel\" Elliott" <camping.elliott@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: "Mike \"Rocket J Squirrel\" Elliott" <camping.elliott@GMAIL.COM>
Subject: Re: An Auxiliary Air Regulator puzzle
In-Reply-To: <bfb5ccc40709261715n2bde8392oac9f2a5a4fb875c0@mail.gmail.com>
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Interesting. Makes sense. I've gone over the plenum -- that thing looks
like a squashed blintz to me -- and the runners and boots and things
pretty carefully looking for leaks and didn't find any. Well, good thing
that I have new boots and gaskets a-comin from the Bus Depot. I'll tear
that mess down and comb it over finely.
Thanks!
Mike "Rocket J Squirrel" Elliott
71 Type 2: the Wonderbus
84 Westfalia: Mellow Yellow ("The Electrical Banana")
74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
KG6RCR
On 9/26/2007 5:15 PM Old Volks Home wrote:
> Only if there is a vacuum leak present in the center air plenum.
>
> Remember, the vacuum flow bypasses the throttle body to reach the plenum
> through the AAR to provide that additional air. The AAR is essentially
> a "vacuum leak", although of a temporary nature when the engine warming
> up - and fuel mixture through the injectors is richer for the first 3
> minutes (and so it needs that air) before the ECU kicks into "Closed
> Loop" mode - about the same time the AAR closes up.
> --
> Jim Thompson
> 84 GL 1.9 "Gloria"
> 84 Westfalia 2.1 "Ole Putt"
> 73 K Ghia Coupe "Denise"
> 72 411 Station Wagon "Pug"
> oldvolkshome@gmail.com <mailto:oldvolkshome@gmail.com>
> http://www.oldvolkshome.com
> ***********************************
> On 9/26/07, *Mike Rocket J Squirrel Elliott* <camping.elliott@gmail.com
> <mailto:camping.elliott@gmail.com>> wrote:
>
> I guess either way you do it, you're restricting the flow of air through
> the AAR? So the result (whether by pinching the hose with pliers or
> plugging the end with your thumb) the engine should slow down.
>
> Is it possible for the engine to NOT slow down when cold when the
> airflow through the AAR is blocked?
>
> --
>
> Mike "Rocket J Squirrel" Elliott
> 71 Type 2: the Wonderbus
> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
> 74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
> KG6RCR
>
> On 9/26/2007 4:32 PM Old Volks Home wrote:
>
> > I've often wondered about that diagnostic/troubleshoot that
> Bentley says
> > about the Aux Air Valve and have felt that it was bogus. The
> best way
> > how you did it - on the bench to see if it closes at all when 12
> volts
> > is applied.
> >
> > In fact the testing procedure outlined for the AAR is similar in the
> > Type 2 68-79 Bentley and it is the same part as used on the Air
> Cooled
> > Vanagons and 83.5-85 Wasserboxers (I've paraphrased and corrected
> some
> > erroneous sub-procedures that if done the Bentley way would have
> created
> > a HUGE vacuum leak at the air intake elbow):
> >
> > "To test the AAR, disconnect its intake air hose from the AAR and
> plug
> > it. Take another piece of hose of the same ID (about 1/2"
> [12mm], about
> > 6" in length and attach it to the AAR. Then start the engine (the
> > engine must be cold). If you cover the hose (during warm-up), the
> > engine should slow down. After several minutes of operation, the
> vacuum
> > should diminish and eventually disappear almost completely.
> >
> > "If the AAR does not close after a reasonable period (in cold
> weather,
> > considerable time may be required), stop the engine. Disconnect
> the the
> > electrical plug from the AAR. Using an ohmmeter, measure the
> resistance
> > between the two terminals on the AAR. The reading should be 30
> ohms.
> > If the ohmmeter reads infinity or the resistance is considerable less
> > than 30 ohms, replace the AAR."
> >
> > Source: Type 2 68-79 Bentley, Section 10, Procedure 4.5, page 12
> > --
> > Jim Thompson
> > 84 GL 1.9 "Gloria"
> > 84 Westfalia 2.1 "Ole Putt"
> > 73 K Ghia Coupe "Denise"
> > 72 411 Station Wagon "Pug"
> > oldvolkshome@gmail.com <mailto:oldvolkshome@gmail.com>
> <mailto:oldvolkshome@gmail.com <mailto:oldvolkshome@gmail.com>>
> > http://www.oldvolkshome.com
> > ***********************************
> > On 9/26/07, *Mike Rocket J Squirrel Elliott* <
> camping.elliott@gmail.com <mailto:camping.elliott@gmail.com>
> > <mailto:camping.elliott@gmail.com
> <mailto:camping.elliott@gmail.com>>> wrote:
> >
> > So I'm looking at the Auxiliary Air Regulator in my 1.9L. It
> is supposed
> > to bypass a little air around the throttle when cold and give the
> > engine
> > a little more pep. 12V from the fuel pump relay applied to
> its terminals
> > causes that bypass to close after a couple minutes. At this
> point the
> > engine can presumably get along fine without it.
> >
> > So Bentley's ( 24.28) gives us a simple test to see if the
> thing is
> > working: start the engine and while cold, pinch the rubber
> hose. The
> > rpms are supposed to drop.
> >
> > Well, they didn't so I moved to the next test: check to see
> if the AAR
> > is getting 12V when the fuel pump is on, and it does.
> >
> > Then to the bench: you can look through the AAR and there is
> a disc
> > blocking the passage, but there is a small hole in that disc
> which makes
> > it easy to blow through. When 12V is applied to the AAR, the disc
> > slowly
> > rotates so the little hole is no longer visible after a
> minute or two
> > and it's hard to blow through.
> >
> > So -- the AAR is fine, the hoses are fine, but pinching the hoses
> > doesn't drop the rpms, as Bentley's say it should.
> >
> > --
> >
> > Mike "Rocket J Squirrel" Elliott
> > 71 Type 2: the Wonderbus
> > 84 Westfalia: Mellow Yellow ("The Electrical Banana")
> > 74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
> > KG6RCR
>
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