Idle settings for Emission Test. Failed first try...

[Jedrik]

Toyota 4age - Turbo. Stock compression. stock CAT

I finally got to the emission test station.
Good news was the cruise passed... but the idle didn't.

Code: Select all

HC ppm     CO%      CO+CO2%      O2%
180        1.3       6                  NA        --- cruse limit
143        1.03     15.23            1.11     --- cruse test (PASS)

220        1.2       6                   NA     --- idle limit
301        2.48     14.78             2.03    --- idle test(FAILED HC and CO)

The test idle RPM was 690. (slower than I wanted) Unfortunately I couldn't datalog the test because the tester uses the cigaret power and my old laptop only runs for a few minutes on battery...

I am asumeing my problem is the idle mixture is too rich. I have the target at 14.7 but the EGO correction is set to slow corection and the VE is set rich in order to get my idle more stable.
After the test I checked the idle AFR and it was about 13.5-13.7:1 AFR.

The stock idle setting is supposed to be 800 rpm (a strugle with lightweight flyweel/clutch) but now I see in the Test Station literature that it needs to simply be less (than 1100 rpm.

So I will try running the speed up a little, that will make it much easyer to stabalise the idle at a leaner AFR.

I also have the idle timing locked at 16 degrees. My repair manual simply states "Idle timing should be at least 16 degrees."

Should I back off the timing a bit for the test?
Also, would going lean of stoak help?

So can anyone add anything I might be overlooking?
I don't know if I failed by a little, and just leaning out will help or if I failed by a lot and there is something else I need to do.

Thanks for any input.

[Jedrik]

I leaned things out on the AFR target table by shifting the table .1 leaner overall and to 15.3 AFR at idle, increased the EGO correction speed and increased the idle to 980 rpm.
This really cleared up the idle exhaust stink and the "buddy" passed the test.
EDIT: lol. "buddy" is the word the forum substituted for my intended b-word... "condition of being born of parents who are not married to one another "

Retest results:

Code: Select all

HC ppm     CO%      CO+CO2%      O2% 
180        1.3       6                  NA        --- cruse limit 
94         0.48     15.08            1.31     --- cruse test (PASS) 

220        1.2       6                   NA     --- idle limit 
119        0.64     13.84             2.89    --- idle test(FAILED HC and CO) 

Now that the government ilk is taken care of, I will work on leaning out the cruse for better economy.

[bluetrepidation]

I know increasing your idle RPM helps with emissions. Interesting to me because there are no emissions tests here but I'd still like my car to be green friendly if possible. Cool numbers.

A.J.

[Jedrik]

Yea, when you dont need power, might as well save some of that premium gas.

The improved smell is the best thing... especialy when fiddling in the garage with the door opened.

I remember when I first got the MS running I would come in and my clothes smelled like I had poored fuel on them. (well, often that was true also...)