*sigh*

[tudor@tvo.org]

Alas, I have figured out the deal with the mileage indicator, and it isn't
pretty.

Basically, your mileage is computed on manifold vacuum and vehicle speed. 
Vehicle speed is taken from the speed sensor, and the manifold vacuum from a
little vacuum sensor.  Both of these are contained in the dashboard -
presumably, on the circuit board.

If your mileage indicator isn't working, there are only two fixes.  Either
the vacuum line is leaking or plugged, or the circuit board itself is broken.
 I pulled the vacuum line off today (and plugged the empty hole in the
manifold, so the engine would run normally), and took the car out for a
drive.  It still continued to give readings, which indicates there's
something wrong with the circuit board.

In the meantime, though, this excercise gave me a chance to go over the
vehicle's vacuum system and replace all of the little pieces of rubber hose
(covered with some sort of cloth material for strength, one would suppose). 
A mete of this stuff from VW was just over $10 - pricey, but worth it in the
long run, I hope.  I was suprised how many of these little hoses in the
engine were on the brink of falling apart.

In the end, I have a happy distributor vacuum advance module, and a
still-defective mileage gauge.  The next step from here is for me to actually
pull apart the dashboard, and see if any of this is user servicable.  Likely
not.

-- Mike


--
To subscribe or unsubscribe, send email to scirocco-L-request@privateI.com,
with your request (subscribe, unsubscribe) in the BODY of the message.