Frequency valve answer....

[waves@epix.net]

I'm not sure you have a frequency valve on your Audi. VW did away with the
frequency valve in late 1985 on most cars. I think Audi did it a year
earlier. This was the switch between CIS w/lambda control and CIS-e. CIS-e
replaced the freq. valve with a device called a 'differential pressure
regulator'. instead of reading duty cycle you now read mili-Amps. This is a
bit more difficult to set-up as most DMM can't see the 10 mA swing. Besides,
usually a 10 ohm resistor block is nec. even if you DMM can read mA.
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                       Rolf Mair is: waves@epix.net
        Racing Resume for Sponsors/Corvettes for sale/Racing Pix @
http://www.sevenwaves.com
    Head Coach and Founder of the Seventh Wave jr. Ski Racing Team @ Doe Mt.Pa
               1994,95,96 East Coast USA SCCA Solo 1 Champion
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