GabrielS

I recently had the smog test and it failed on two counts. The HC measured 202 ppm, max allowable is 104 @ 15 mph and at 25 mph, it measured 86 with a max allowable of 121. The CO % measured 1.36 with a max allowable of .89 @ 15 mph and at 25 mph it measured 1.56 with a max allowable of .69. Other than that it passed all other criteria. Is this a symptom of failed cats or could it be something as simple as an adjustment? I use the Colortune method of adjusting the fuel mixture and follow the service manual to the letter for other adjustments.The last time it was smogged was in 2009 and was informed it barely passed (I don't have the stats from then immediately at hand). Any help in having it pass smog would be appreciated.

thatpoorguy

you can crank it lean till you pass the test, but dont drive far as you're running a high risk of detonation. rotaries are notorious for failing emissions tests, even fairly new rx-8's

GabrielS

I'm experimenting with Lucas brand fuel system cleaner plus giving the engine a concise tuneup, recheck tire inflation and hoping for the best. The fuel system cleaner supposedly helps with the emissions after using a tankful of gas. Snake oil, maybe, but worth a try.

I noticed a couple ball bearings in the line leading to the shutter valve solenoid while inspecting the rats nest of solenoids. I had the shutter valve replaced a few years ago but just noticed this anomally now. Instead of replacing the valve, could the mechanic have inserted these ball bearings to simulate proper shutter valve function? Your thoughts on this would certainly be appreciated.

boyee

try running Seafoam through your gas tank. Get the fuel level to just about empty (1/8 tank) and pour the whole bottle of Seafoam in the tank. Then drive it like you stole it. There will be a smoke screen coming out of your exhaust. That should clean up some carbon deposits in your engine as well as cat. If not, make sure all of your emission system components are functioning (air pump, air control valve, etc.) and your timing is spot on. Also change your engine oil and filter. If all else fails replace your cat. Rotary Performance in Texas (rx7.com) sells Bonez cats that are high flow and supposedly can withstand the heat of a rotary. It helped mine pass with flying colors.



Turning the fuel mixture to be leaner will only affect the mixture up to 1000rpm as it is only for the idle circuit. Anything above 1000rpm, the idle mixture and speed screws will not affect your engine performance.