On Thu, 30 Jan 1997, Donald Baxter wrote:

> I have been having problems with steady idle, intermittent, and 
> usually after the van has been running at high speed for at least 30 
> minutes.  At idle, the van will rev up to around 1400--1600 RPM and 
> then drop down to normal, slowly rise again and then drop back down.
> 
(snip)
> 
> Donald Baxter
> '85 GL Vanagon

   I found this condition to be brought on by 1 of 2 things:
      1 - Thermostat opening up to soon, and keeping engine
          to cold.

      2 - NO O2 sensor in the system.

   FIx: Drive Van for 15 min. and made sure temp. gauge is up to
        middle after running hard. This will check temp. Old
        Thermostats gets lazy and tend to run cool.If OK,
        Check wiring to the O2 sensor and the sensor it self.
                                                ERic Zeno