So for all those years you had one or more of the following:
Ignition miss fire
Lean miss fire due to bad injector(s), vacuum leak, cylinder air flow
unbalance due to cylinder, rings, or valve problem.
Valve problem-exhaust.
Oil carry over from overfilling, worn guides, or intake valve stem seals
missing.
Improperly adjusted ignition timing, (over advanced)causing throttle to be
too far closed, insufficient air for combustion, mixing at idle speed.

In addition the catalyst was not doing its job.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Stuart MacMillan
Sent: Friday, June 29, 2012 12:05 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Tips on passing emissions

At least they worked 10 years ago.  As I mentioned in an earlier post I used
to have to go to a test site where a guy with a Sun three gas tester charged
$35 to guarantee you passed.  No matter how much tuning I did, and I would
even set the mixture screw to get the proper voltage at the O2 sensor, I
always failed on HC, and he did two things.  First he cranked up the idle to
the maximum the test facility allowed, which was 1150 rpm.  The second, and
most important, is that he was able to talk the tester out of using the
funnel they were supposed to stick on the wand for short tailpipes like the
Vanagon's.  I think that had the most to do with it because without it there
was more air dilution of the exhaust gasses.  That stupid funnel kept the
gasses in the tailpipe longer, and I didn't think it was fair.  They didn't
listen to me though.

These were the days before we had dynamometer testing, so YRMV.  Syncros are
not dyno tested though for obvious reasons.

Good luck!

Stuart

Exempt '85 Westy

Seattle