Pirate 4x4 banner
1 - 1 of 1 Posts

853 Posts
Discussion Starter · #1 ·
I've got a 22R with a Weber 32/36 carb, LCE cam and headers, Engnbldr ported head with oversize valves, most of the emissions equipment is off except the PCV valve and the catalytic converter. I've got it to pass before in this condition but this time it didn't. Washington just has HC (hydrocarbons) and CO (carbon monoxide) testing on rollers at idle and 25 MPH. The only other thing is you have to have enough CO and CO2 coming out of the exhaust pipe to show the engine's burning fuel and the exhaust is good.

The first test showed the CO at cruise being over 2 times what it should: allowed 1%, the reading was 2.69. The others passed but not by much. I changed the main jet on the carb to make it run leaner and it worked, it went down to .11%. The bad part is the HC at idle shot up to 700 PPM and the allowable is 220 PPM.

I tried a bunch of stuff, adjusting the idle jets and mixture, checked for intake leaks, timing, plugs, cap and rotor, even tried putting 9 parts gasoline and 1 part alcohol in. None of that stuff worked at all, because it was in good shape to begin with. I changed the catalytic convertor and it passed no problem. I'm guessing running rich made the cat go out prematurely.

Now the HC is 55 PPM at idle and 38 at cruise, allowable at cruise is 150 PPM. The CO is .03% at cruise allowable is 1%, CO at idle is 0, allowable is 1.2%.
1 - 1 of 1 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.