Hi Everyone.  Well, I took in the Polar Bear in today ('90 Syncro) for 
it's annual Air Scare Emissions test, and it passed with flying 
colours :)  However, I see a trend in these results, and would like 
to bounce this off the members of this list;

Being a Syncro, they couldn't put it on the dyno to test NOx 
emissions, HC and CO were the only tests performed, but with the 
engine free of any load.

We have only had emissions testing for four years in British 
Columbia, and the CO count has been 0.00 for the past 4 years... so 
much for commiting suicide in the garage, eh?  :)

Here's the trend in HC emissions for our van;

 99,000 km    5.00 ppm   Nov/93
111,000 km   8.00 ppm   Nov/94
126,000 km   3.00 ppm   Nov/95
134,000 km 18.00 ppm   Nov/96

Maximum allowable is 240.00 ppm.  The van is running on Bosch 
Platinums from last year (they are clean), Chevron Supreme 92 fuel, 
clean air filter, 24 mpg (imperial), oil change 2 weeks ago,  and is running very well.

My questions are;  Is this trend due to an emissions part starting to 
fail?  Should I be concerned about this trend, or just pass this off 
as "general" fluctuations in the test equipment, humidity, 
temperature during testing, etc??

Ideas?

Harry. 
---------------------------------------------------------
Harry Yates, Langley, BC, Canada
'90 Syncro Westfalia www:   http://www.bcit.bc.ca/~hyates
'87 Golf Diesel      email: hyates@bcit.bc.ca
'91 Miata (Millie)