LC1 wideband reading lean but meagatune reading rich

johnhickey · Post by **johnhickey** » Thu Apr 13, 2006 12:05 pm

System: MSII, embeded 2.32, MT 2.25, V3 main board, Innovate LC-1 wide band.

I have the engine running on a dyno at a steady condition.

Using the logworks software supplied with the LC-1 wideband O2 sensor the A/F ratio is reading 18:1 and flickering a little as it should be. Megatune however is reading 12.1 constant. I have verified the analog output of the LC-1 is putting out the correct voltage all the way to ADC5 on the MSII daugtercard. The .ini file is configured for the LC-1 wide band sensor. Data log of ego parameters is below:

egoVoltage AFR1 AFR2
12.1 12.1 12.1
12.1 12.1 12.1
12.1 12.1 12.1

Can some suggest a process to debug this issue?

darkstarmedia · Post by **darkstarmedia** » Thu Apr 13, 2006 12:16 pm

Be sure your sensor ground and the MS ground are in the same place. these must be tied together. if they are not you will see different readings.

johnhickey · Post by **johnhickey** » Fri Apr 14, 2006 3:40 am

Thank you very much for the reply Richard. The grounds were definatly a good idea, however I double checked them & they are tied together.

I do have a 3.6-3.7V signal at AD5-1. This should be around 18:1 A/F using the default LC-1 calibration of 7 to 22 A/F = 0-5V.

Attached is a PDF graph from a data log showing A/F ratio clipping at 12.1 on the low side but jumping to 14.6 during a portion of a run. This leads me to believe the signal is there but not scaled or configured properly.

How can I verifly in the Megasquirt-II.ini file that the proper configuration & scaling is there?

johnhickey · Post by **johnhickey** » Fri Apr 14, 2006 4:56 pm

I determined I had not calibrated the Ego sensor in megatunes calibrates sensoir menu. All is well