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Calibrate AFR table did something bad

Posted: Thu Apr 13, 2017 1:43 pm
by Jamesl
I've been trying to use Tuner Studio Analyze Live and I keep getting O2 out of range. Doing some reading I saw where you could use the Calibrate AFR tool to specify your 02 sensor and I thought that might help. I have an ancient LC1. It had been giving me reasonable readings, typically in the range of 12-15 for the past couple weeks of tuning. When I used the Calibrate AFR tool, specifying Lc1-Lc2 (default), the O2 sensor started reading 20+ full lean no matter what I've done. I did a restore to previous msq from a few days ago, and that didn't help. I went in and recalibrated the Lc1 to insure it was set to 0v = 7.35:1 AFR, and 5v=22.39 AFR. Again, no help.

What would cause this weird behavior? How do I get back to where I was?? :cry:
afr screen shot.jpg

Re: Calibrate AFR table did something bad

Posted: Fri Apr 14, 2017 6:09 am
by LT401Vette
Do you have any idea what your LC-1 is calibrated to output?
It used to be common to have them set up for 10:1-20:1 0-5v, but also 1V-2V was sometimes used.
The 1V-2V would lively make it read very lean with a normal default LC1 cal on the MegaSquirt.

When is the last time you calibrated the O2 on your MegaSquirt? Any idea what it was calibrated for?

Re: Calibrate AFR table did something bad

Posted: Fri Apr 14, 2017 6:43 am
by Jamesl
As I mentioned in my post, the Lc1 is programmed to 0v = 7.35:1 AFR, and 5v=22.39 AFR, which is the factory default for wideband on output 2 of the LC1. I did a clear air calibration of the sensor itself a few weeks ago.

I'm thinking this has to be a software glitch, but certainly could be wrong...

Re: Calibrate AFR table did something bad

Posted: Fri Apr 14, 2017 6:56 am
by jsmcortina
Enable the "Exhaust gas Volts" gauge on your dash too (right-click on a gauge) and see what that is showing. This should help you determine whether the wideband is sending out the wrong voltage or whether the ECU is interpreting it incorrectly.

James

Re: Calibrate AFR table did something bad

Posted: Fri Apr 14, 2017 8:25 am
by Jamesl
Thanks, James, I didn't know that was an option. I will give it a try.

Note: "Exhaust Gas Oxygen1 - egoVGauge" on the 3.0.18 version of Tuner Studio.

Re: Calibrate AFR table did something bad

Posted: Fri Apr 14, 2017 3:43 pm
by Jamesl
In the magical world of computer stuff, the problem resolved itself overnight. I have no clue why. :? I did put up both the afr1Gauge and the egoVGauge side by side and they both responded just as they should.