Re: quattro-digest V3 #885

[baselope@netwide.net (Robert Riley)]

>Am I correct in saying this is the small sensor located on the underside of
>the water outlet which is bolted to cylinder head between 1st and 2nd spark
>plug? There are two sensors on this water outlet, one below (small with
>single round terminal) and one on top (bigger with single flat terminal).
Yes...
the one that has the round connector is for the temp gauge.  The one on 
top should have a connector that has 2 pin connections in it...just look 
for 2 wires comming out of the connector.  These give the computer 
information about the water temp.  With the wrong info being sent by a 
bad sensor, the computer will run full rich which will cause the problem 
you have described.  It is a very common problem.  The guy at the shop 
can test for it with a test plug (just a fixed resistor, but I don't know 
the OHMS).  

I am sorry to hear that you have spent so much time and money on this,  
but it sounds as if your car (motor at least) will last quite a long time 
and benefit from the extra work.

The sensor on the bachk of the head is for the cold start valve.  It 
allows the valve to fire extra fuel into the air accumulator when the 
coolant temp is below 36F. It only allows this for 5 seconds and then it 
shuts down to prevent flooding the motor.  If you suspect that this is 
the cause of the over rich condition, just unplug it.  It is not 
neccessary for normal operation.

Good luck,  and let me know how it comes out.