John,
   I would check the resistance of the TEMPII sensor when it
is cold. Instead of trying to interpolate the chart in the
Bentley I just compare it's value to the TEMPI sensor. They
should be within ten percent. Of course this only works when
they are at the same temperature.
   Have you checked the cold idle air valve? It is bolted to
the passenger side head. Bentley has an OK procedure to
check it. In the life of our 85 GL I had to take the valve
out out once a year and run carb cleaner through it to
un-stick it.

      Ken Lewis
 86 Transporter Crew Cab, 60 T-5 Coupe
 http://neksiwel.20m.com/   O2  sensor monitor gadget, my
cars, Vanagon Tech
 http://EB03.20m.com/  Everybus 2003  pictures