Joe,

I'm sure I'm checking it right.  Behaves the same way both by checking at pins 2-3 (center two)
and by touching the board.  

Here are the values, in kohms, measured both at the pins and by putting a probe on the carbon track where the wiper are contact would be (and closest to the taps, because the carbon track obviously has its own
 resistance:  Here's what I get:

               pins 3-4    on carbon track

closed      500             500
1             1100           1100
2             1100           1500
3             1100           1500
4             1100           1800
5             1100           1200
6             1000           1100
7               950           1000
8               900            1000
9               800            1000
open          300             700

  ----- Original Message ----- 
  From: Joe Romas 
  To: Steve Gough 
  Sent: Saturday, May 12, 2001 2:05 PM
  Subject: Re: AFM Testing?

  Steve,

  Something dosen't sound right! It should keep rising in a steady line with no dips or rises and keep going up untill it reaches the end. Are you metering it at the pins or somewhere on the board?

  Joe
    ----- Original Message ----- 
    From: Steve Gough 
    To: Joe Romas 
    Sent: Saturday, May 12, 2001 2:56 PM
    Subject: Re: AFM Testing?

    Thanks, Joe.

    What's wierd to me is that neither unit shows a steady increase or decrease
    in resistance as the flap is opened.  More like a "hump", i.e. resistance slowly
    rises until about half open, and then falls again.  It's lowest at either end of the
    travel.  Make any sense?

    Steve
      ----- Original Message ----- 
      From: Joe Romas 
      To: Steve Gough 
      Sent: Saturday, May 12, 2001 12:59 PM
      Subject: Re: AFM Testing?

      Steve,

      The one with the drop-outs is bad! The resistance should rise steadilly as you move the arm from idel position. When the computer gets to the "drop-outs" it sees it as a lot of air and adds more fuel and that's when things go south as far as running go.

      Joe

        ----- Original Message ----- 
        From: Steve Gough 
        To: vanagon@GERRY.VANAGON.COM 
        Sent: Friday, May 11, 2001 4:06 PM
        Subject: AFM Testing?

        Dear List,

        I'm trying to tell if I need a new air flow meter for my '86 Vanagon.

        Can anybody enlighten me on how resistance should change
        as the vane moves?  My manuals (even Probst) are vague.
        I have two AFM's in hand.  Both show similar resistance changes
        with movement, but one seems to have some drop-outs.

        Couldn't locate anything in the archives.

        thanks,

        Steve

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