My 83.5 1.9 wbx does this too. At start it goes on fast idle, then
into cyclic idle. eventually it settles down to a smooth idle. Would
these symptoms fit your "cure"?

On 17-Dec-07, at 8:41 PM, Automatic digest processor wrote:

> On Monday, December 17, 2007, at 02:13  PM, Automatic digest processor
> wrote:
>> Date:    Mon, 17 Dec 2007 15:29:54 -0500
>> From:    AAG - Larry Word <word_aag@COMCAST.NET>
>> Subject: 1985 Vanagon - New Year's resolution - AFM
>>
>> It's time to finally fix my "hunting idle" on my vanagon.....
>>
>> I drive this van daily but it's idle has been unstable - "hunts -
>> with
>> =
>> peaks and lows" - for many years now...its idles like a old harley =
>> motorcycle....
>>
>> Where do I start looking to fix this symptom?
>
> There are two easy-enough possibilities; one is idle set too high, and
> the other is a bad O2 sensor.
>
> In the first condition the idle raise up until about 1500 or so, then
> cuts abruptly down, repeats.  Screwing the idle screw on the throttle
> body in (clockwise until the idle is around 900 rpm will fix it.
>
> The second condition is caused by the computer hunting for the correct
> mixture because it's not receiving a good signal from the O2 sensor.
> If it goes away by unplugging the sensor, you need a new one.  They do
> wear out and/or can be damaged by a rich running condition or if you
> overfill the oil.
>
> Hope this helps,
> Gregory Smith
> Olympia, WA
> '84 Vanagon
> '88 Vanagon
> '87 Bertone X1/9 Corsa
>