I just failed my bi-annual emissions test. My results were:

Cruise

HC 50 (limit 220 ppm) pass
CO 0.00 (limit 1.20%) pass
CO+CO2 14.28 (>= 6.00%) pass

Idle

HC 340 (limit 220 ppm) FAIL
CO 0.00 (limit 1.20%) pass
CO+CO2 11.70 (>= 6.00%) pass


I'm guessing with the S3 cams I have excessive overlap and that is what is causing the high HC emissions at idle. Since I have the JWT cam gears I was thinking of advancing the exhaust cam 2.5 degrees and retarding the intake cam 2.5 degrees. Anyone disagree?

Steve

Is your timing turned up? Bringing it down a little, and using lower octane gas will help.

It took most of my afternoon but I passed!

I retarded the intake cam 2.5 degrees and advanced the exhaust cam 2.5 degrees all in an effort to reduce overlap. This was the only change I made.

Results

Cruise

HC 72 (limit 220 ppm) pass
CO 0.19 (limit 1.20%) pass
CO+CO2 13.99 (>= 6.00%) pass

Idle

HC 144 (limit 220 ppm) PASS
CO 0.00 (limit 1.20%) pass
CO+CO2 13.33 (>= 6.00%) pass

Steve