Date:         Tue, 3 Apr 2001 11:19:12 -0400
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: AFM values
Comments: To: James Creech <jacreech@visuallink.com>
In-Reply-To:  <003801c0bc4d$9e7befc0$704397ce@jimc>
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 10:51 AM 4/3/2001, James Creech wrote:
>Yep, you're right.  Hadn't thought of the spring tension.  However, the
>relative values across the wiper spectrum would still yield some useful
>info, I think.

Yep.  Might be easier? more useful? -- different anyway <g> -- to graph
voltage against position instead of resistance, since voltage is what the
ECU actually sees.

>  Additionally, if the AFM is new, presumably there would be a
>preset factory tension on the spring that would not vary terribly much from
>one unit to the next -

That's where I wonder a little -- if it were a Japanese product I would
expect it to be manufactured so it was in spec to begin with, but with this
I have a suspicion that there's a roomful of gnomes with calibrated vacuum
cleaners somewhere, tweaking them up before they get shipped.  Have you
looked at the fuel/temp gauges?  They each have mechanical "zero" and
"span" adjustments (in quotes because they interact like crazy) accessible
from the outside.  But data will answer these questions, of course.  Could
be useful if you could develop a standard protocol for measuring with the
cover still on, makes the pool of ...er...potential numbers a lot bigger.

d

>so those of us with AFM's not yet tampered with
>(spring tension unchanged) could still make a helpful comparison before we
>try our own adjustments.

David Beierl - Providence, RI
  http://pws.prserv.net/synergy/Vanagon/
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"