Date: Sat, 17 Oct 2009 18:18:32 -0400
Reply-To: Chris S <szpejankowski@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Chris S <szpejankowski@GMAIL.COM>
Subject: Re: AFM adjustment - flap, slider, spring wheel voodoo question
In-Reply-To: <4ad90227.25c0100a.356c.2a18@mx.google.com>
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David,
thanks for help. I got some sleep, which helped, and took another look
at it in the morning. My previous problem was getting the mixture rich
enough at high rpm. I had to relax the tension spring to the point
that the air flap did not close when engine was off. This morning I
turned the wheel just enough to close the air flap and was able to get
the mixture close enough to display .6 volts at 3k rpm as 2k and 1k. I
was also able to dial in the idle mixture.
Not sure what happened yesterday, but I suspect it was a voltage
measurement issue on my part.
This episode makes want to buy one of those O2 monitor displays,
although I shouldn't have do this again for a while.
2009/10/16, David Beierl <dbeierl@attglobal.net>:
> Hi Chris --
>
> At 06:00 PM 10/16/2009, Chris S wrote:
>>http://www.thesamba.com/vw/forum/viewtopic.php?t=356377
>>
>>Is this a good way to adjust?
>
> Mechanical or not, that guy is a good engineer. If you understand
> and pay close attention to *all* his advice, including careful
> reading of paragraph two, I don't think you'll go *far* wrong. If
> his explanations don't make sense to you or if you tend to be a
> little slap-dash about things, then I think you're better off not
> messing with it. Bosch set these things up at the factory and they
> don't expect their characteristics to change during their working life.
>
> Note well that the method is intended to take an AFM that's out of
> adjustment and get it close enough that the feedback from the O2
> sensor can bring the mixture into the range needed for the CAT to
> work correctly. How close that is to the original calibration of the
> AFM I haven't a clue.
>
> I think that in terms of killing the engine, the danger is of getting
> a mixture that's too lean under some conditions. Dennis Haynes can
> tell you lots more about that than I can.
>
>> What is the actual spring tension function
>>vs. the slider tweak?
>
> Read footnote four again, and then the wiper/spring instructions. If
> you still don't understand, pmail me and we'll sort it out.
>
>
>>the above procedure the engine has awakened. I'm still not getting the
>>voltage at high RPM the procedure says I should.
>
> Would you quote the part you're talking about, and what your results are?
>
> Yrs,
> David
>
>
--
Chris S.
Disclaimer: "Death and serious injury may occur"
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