Hi Volks,
     All vanagons tend to do this, when you notice this slight stumble the
ecu is in closed loop. Another way of checking for closed loop is to hold a
steady throttle at about 3k (any rpm is good I just like 3k). If in closed
loop you will notice the rpm vary slightly at 2-5 second intervals. This is
the mixture going from rich to lean as the ecu hunts constantly for the
perfect mixture but never quite gets there.  The faster the repetition the
better condition the o2 sensor is in.

Midwesty

----- Original Message -----
From: "Mick Kalber" <hotlava@INTERPAC.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Sunday, October 29, 2000 3:05 PM
Subject: Re: 85 with uneven idle

> >every 5 seconds or so the idle speed drops, the engine stumbles slightly,
> and then it comes back to normal speed.<
>
> I've been meaning to ask the list about this... every vanagon I've ever
> owned does this (86GL, 88 Wolfie, 89 Syncro Westy)... stumbles slightly
> during idle.  I was under the impression that it was normal... yes?  But,
as
> Greg asks, why?
>
> Mick Kalber
> 89 Syncro Westy "Daddeo"
> Tropical Visions Video, Inc.
> 62 Halaulani Place    Hilo, Hawaii  96720
> ph. 808-935-5557    fax 808-935-0066
> hotlava@interpac.net
> www.volcanoscapes.com
>