Also what is good idle air/fuel and cruise. Right now idle is at about 13.1 and cruise is fat at about 12.1. Wot is 12.5 to 1. Help?????
When using a O2 data logger..caution.
Make sure all your HT leads , plugs etc are in top condition and everything is firing 100%.
A slight , undetectable misfire will come up as a lean condition, because of increase in O2 levels...a miss fire maybe under load (plug gaps) only.
This is where a data logger using O2, a MAP (vac) , advance, and maybe throttle postion...then reveiw logs later will pick up stuff like that.
Not being 100% sure all is correct can get u and the engine into a lot of trouble.
Do not rely just on a O2 gauge for tuning
A vac leak will generally give incorrect readings right across the board.
Ideal AFR is 14.7.
One goes for either ecomony mixtures or power mixtures
Idle around 15 to 15.5...a leaner mixture u can run more idle advance...and smoother idle.
Cruise 30 mph same as idle
Cruise 60 mph will drop due to slightly heavier loads (wind etc) 14.7 to 15.0
Light load up a slope 14.5 to 15.0
WoT 13 to 13.5
Idle basically as above, 15 to 15.5
30 mph cruise 14.6 to 15.0
60 mph cruise 14.4 to 14.7
WoT 11.5 to 12.5.
Be 100% sure the O2 sensor calibration is correct.....in fresh air should read 20.95%
If the O2 sensor has been positioned correct, not in a low spot of the exhaust, over night check will show about 20.9% as a quick check....If not located in a good spot, HC gases are heavier, tend to hang around and the O2 will read lower than 20.9%
Use a logger for tuning, do not use a gauge...they are not quick enough response to give accurate reading for tuning purposes.
If you data is faulty, everything falls apart....Caution.
If correct, the results are dramatic.