CIS-E3 problems - temperature sensor?

[Eyvind E. Spangen]

I found a guy around here with an Audi 80 with the same engine, so I'm going
to try his ECU to see if it changes anything. All switches/sensors measure
OK, but the DPR current goes way off with the temperature sensor connected.
I know ECU's mostly don't go bad, but when I can swap another known-good in
for free, I give it a try next week.. :)

For the O2 sensor: Just unplugging the O2 sensor while idling will probably
not make a noticeable difference, O2 sensor working or not. If you unplug
the O2 sensor, the ECU will just "guess", or more correct, use a map to
calculate. Pretty OK, but not 100%. If you measure your O2 sensor with a
voltmeter (analog preferable) with a reading from 0-1 or 0-2 volts (unplug
the O2 sensor from the harness in car, connect red cable of multimeter to
the O2 sensor, black cable to ground), you should see the O2 sensor give an
output voltage around 0.5 volts, and the output should be swinging a little
bit up and down. Just blip the throttle slightly, and you should see the
reading change. If you get no output and are 100% sure everything is
connected, or it doesn't swing up and down, it's probably time for a new O2
sensor.


Correct me if I'm wrong, it's taken from memory. Check out Huw's site:
http://www.humanspeakers.com/audi and select "Tuning CIS-E" for more info
about checking and adjusting the system. Just one note: If nobody has messed
with the mixture adjustment, you probably don't need to either. If something
is off, in 9 out of 10 cases, it's something else (air leak etc.) that
causes it.. :)


2009/9/29 L DC <ldc007usa at yahoo.com>

> Not to highjack Eyvind's thread but this goes along the lines.
>
> John, as in Eyvind's case, and as per the suggestion of a QSW Syncronized
> lister (http://autos.groups.yahoo.com/group/syncronized/), I have also
> done that quick test of unplugging and plugging O2 sensor on my VW QSW (JT
> code) to determine its effectiveness.
>
> No difference what-so-ever.
>
> Could you elaborate on that if you would please?
>
> From what I'm told, if my QSW has bad O2 sensor, the ECU would take over
> and make an estimated guess as to the ideal mixture of air/fuel?
>
> BTW, my car seems to run just fine, idles, runs and accelerates just fine.
> But could the car be running with no O2 input?
>
> -Regards,
>
> -Louis
>
>
> --
MVH/MfG
Eyvind E. Spangen