Hi,

Check the Temp II wire connections for corrosion or breakage, especially
near the connector. (actually check all the connections you can while you're
in there. Especially ground straps. Same thing happened to me (panic time)
Also make sure no vacuum leaks or  corrosion on wire connections and ground
to the O2.

Wish I could say I know these things cuz I'm so smart.....but I can't.
Learned it all from the great people on this list.

Cheers,
Katy
> Hello, I replace the idle control unit on my '88 Vanagon and the result is
> that it runs fine for a while, then the idle will jump up to 2200rpm and
> refuse to return. Even turing the ignition off then on makes no difference.  I
> did clean out the idle valve when I replaced the electronics.  The o2 and temp
> II sensors were replaced a year ago...................