ok, I went and did the emissions/smog check today with my samurai.  here is what I have: Weber 32/36 DGV carb with 45/50 jets, isky torquer cam, bored .020 over, stock compression, header, 2" exhaust with new catalytic converter.  

my problem is, while I pass with flying colors on all other criteria, I cant get my idle hydrocarbon emissions down enough to pass.  I am registering 348 PPM when the limit is 220 PPM.  I'm idling at 1100 rpm, with an A/F ratio of about 16.5:1 according to my wideband O2 gauge.  I do suffer from some slight misfires at idle, which may be putting me over the limit, but I'm not sure.  I'm about to go so far as to run 25% denatured alcohol to make this thing pass, but I dont want to damage any seals with it.  

what suggestions do you guys have to help me pass?

thanks in advance for any help.

2 ounces of acetone, but sounds like your idle is way too high, hows your initial timing ?  I'm thinking advancing it 2-5 degs might get more complete burn
http://pesn.com/2005/03/17/6900069_Acetone/

I'm not sure what my initial timing is, as I time the engine by ear, and drive it.  I advance the timing until I can get it to ping and then back it off about 1.5-2 degrees to maximize power without pinging.  I have been told this is the "british style" of tuning.  works for me so far, and I usually have it idle about 800 ish but the emissions guy told me to bring it up to 1100 and it did help with reducing the idle hydrocarbons.  I am going to try denatured alcohol tomorrow on my friends urging.  hopefully it will work

Seafoam does magic, for both ruff idles and emission test.

Hydrocarbons were just a tit high on my pickup last fall. I tossed 3 bottles of heet into the gas tank, drove 15 miles. 40 minutes after failing, it passed.

 Re: the joy of emissions testing:  questions......
« Reply #1 on: Apr 14th, 2005, 6:53pm »  Quote  Modify  

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2 ounces of acetone, but sounds like your idle is way too high,


bandit86, what does the acetone do, and does it hurt anything?