Mixture control can be easily tested using the oxygen sensor and a good
voltmeter. If you have to buy a meter look for one that also has a bar graph
display and this will respond much faster than the numbers and give you
visual.
What you want to see is the system going below and above ~.5 volt. If you
stay above .7or .8 volt you are running rich. Check grounds and the temp 2
sensor. If staying If not fluctuating at all, check the O2 sensor itself.
Get yourself a battery. Disconnect the sensor and put the meter on it. With
engine running you can connect the lead to ground, the engine should go rich
and you should see the sensor voltage go up.   Now use the battery, positive
to the lead and ground the negative. The engine should lean out and you
should see the sensor voltage decrease. This test is in the Bentley.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Van Pelt, Steve
Sent: Thursday, January 15, 2015 12:03 PM
To: vanagon@GERRY.VANAGON.COM
Subject: 2.1WBX running rich

Hi all,

My water boxer motor is running slightly rich, or at least I feel like it is
since I don't have a smog meter. I have done all the usual checks such as
disconnecting temperature two sensor, disconnecting the oxygen sensor,
checking with a can of carb cleaner to see if idle changes when I spray
around the intake manifold hoses. New air cleaner installed.
The idle also is kind of an issue, in the sense that it will idle at about
1000 and hunt between 1000 and 1200 RPM. That is with the idle screw on the
manifold screwed all the way in tight. If I backed the screw out, it runs up
\ to 2000 rpm quickly.

Any other thoughts on what to look out for?

Thanks,

Steve