"Seat of the pants" setting of the CO is hardly ideal and I think
you'd be better off to have this done at a shop.  However, the book
"Bosch Fuel Injection and Engine Management" has this to say:

"If a CO meter is not available, adjust the mixture for the leanest
setting that provides a smooth idle, then enrich the mixture an
additional 1/4 turn.  Test drive and check for surging at part
throttle.  If so, enrich 1/4 turn at a time until the surging
disappears."

Obviously, this is written for the normal way of setting the mixture -
turning the adjusting screw - so you'll have to modify it to your
circumstances.  I think the way I'd approach this is as follows:

1) Turn the adjusting screw all the way in, then turn out 2-3 turns.
2) Open up the AFM, mark the original position of the wheel.
3) Tighten the AFM spring by, say, 7 teeth.
4) Close up the AFM, securing the cover with tape, and try the above.

The cover of the AFM should be air-tight.  Naturally, you destroy this
seal when you pry the cover off, so try to restore the cover to its
air-tight condition when doing your adjustments (hence, the suggestion
for tape around the rim of the cover while testing out your
adjustments) and be sure and seal it back up when you're done.
----------------------------------------------------------------------
-----
Tom Young                      tomyoung1@home.com
Lafayette, CA 94549        '81 Vanagon
----------------------------------------------------------------------
-----
----- Original Message -----
From: "Patrick Callaghan Jr." <patcal@QWEST.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Thursday, March 08, 2001 8:47 AM
Subject: AFM spring adjsutment

> I have to adjust the spring tension on my 82 westy without a O2
sensor.  I
> know I have to increase the tension to lean out the mixture.  The
adjustment
> screw comes all the way out & I still only get down to 2.5% CO.  Is
there a
> way to do this without the O2 sensor?  I have a digital VOM but
would not
> know where to hook it up.  Any input would be appretiated.
>
> Pat Callaghan
> 82 Westy
> Portland, OR.
> www.users.qwest.net/`patcal