When I bought my 85 Vanagon, the O2 sensor was disconnected.  I reconnected
it and found that it ran too rich so I bought a new one. ( also a temp 2
sensor)  All was well for 2 months/3000 miles and now I run too rich again.
 I disconnected the O2 sensor and it doesn't appear to help, although I
have not given it alot of time yet.  Also when I did this I tried to bring
the the down to 850 rpm from 1000 rpm that it is now.  With the O2 sensor
disconnected, I screwed the idle screw all the way in, and I still have
1000 rpm. So to sum up , the O2 is disconnected, idle rpm is 1000 with the
screw full in and I'm too rich. (unfortunately not $$).  Any advice ?  ps.
I have not checked the current O2 sensor's ohms.

Thanks,
LJ