Vehicle speed signal in Typ 89

[Dave Hord]

Radek,

The jumping speedometer is usually caused by a broken solder joint inside the
instrument cluster. The repair is to carefully disassemble the cluster
following all contact paths and checking each solder joint (the best method is
to start at the speedometer and work your way out).  I would suggest that
broken solder joints account for 99% of all speedometer jumping problems (in
the 90 series at least).

The combination of the fuel consumption jumping to three times above normal is
a new one i haven't heard of, and not something I notice with my (currently
jumping) 90q speedometer.  The trip computers are notorius for being wrong,
however, and I don't pay much attention to it besides "KM till empty".  It's
always way off, but after 5 years with the car I know that 200km left
means 'start thinking about gas' 110km left means 'hey, you're on empty' and
80km left mean 'DUDE! BUY GAS!'  I haven't discovered which value is "oops,
should have bought gas"...but at 80km left, there are only 4L in the tank!

HTH,

-Dave
--
86 4ksq 266,600km new to me as of March 5th 2003... will it stick around??
89 90q  330,000km as of Feb 26th.
Rally Conversion...perpetually in progress...
Roll cage shots available at:
http://home.the-wire.com/~spokes/rollcage/page1.htm


Quoting radek at istar.ca:

>
> Hello fellow Audifans.
>
> This weird thing has been happening to my 88 90Q lately:
>
> from time to time, while driving, the speedometer needle starts to oscillate
> (about 5 km/h
> amplitude)
> and the fuel consumption display goes crazy, showing consumption three times
> higher than
> normal.
> There is no noticeable difference in how the car behaves.  The problem comes
> and goes
> without
> any pattern.  Overall fuel consumption (mileage between tanks) seems normal.
> No error
> codes.
> Is the vehicle speed signal screwed up somehow?  How can I test it?
>
> I should add that the O2 sensor is nearly new, the temp. sensors (both, the
> upper and the
> lower) have been
> replaced, but the car idles high (about 1000 - 1100 rpm.).
>
> I'll be grateful for any tips, this thing drives me crazy.
>
> Radek
> 88 90Q
> 91 V8Q
>
>
>