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Subject:Re: AFM adjustment - flap, slider, spring wheel voodoo question
From:David Beierl
Date:Fri, 16 Oct 2009 19:30:44 -0400

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