Troble Logging AFR's
 

I am having a bit of an issue, datalogging with my E6X, using Halwin v 1.26. I am trying to datalog my 0-5 volt output from my wideband O2 meter (diy 2A0). I am reading between 0 - 5 volts with my voltmeter, coming from the wideband controller, so I know it is working properly.

When I hook it up to the Oxygen sensor input on the E6X, I can log mV input, but when I do the conversion to AFR, the number is always about 2 points higher that what the actual AFR was (i.e. - meter reads 12.5, in excel I am getting 14.5). I am using the formula 2*AFR/1000 + 9, which is what is suggested from the manufacturer. What is strange is that the mV reading I can see coming out of the wideband controller, is not what I am seeing, when I look at the datalog in Excel.

I decided to try using the spare A/D to see if that would make a difference. I hooked up the wideband output to the red/black wire, and set the setting in the software to General. when I look at the datalog for spare A/D, the number is 1745, and never changes. I have not tried selecting UEGO or O2 sensor, which I will. I don't see how that will change the logging on that input.

Sorry for the long winded post, hoping someone might have some idea.

Thanks,
Greg

I have talked to a couple people about this recently. It's been two years since we ran our drag car with the E6X (just installed the new 20B and the PS2k will go in soon!!! :) ) so I am a bit rusty but we used the O2 input and logged in mV and then did the conversion in Excel like you tried the first time. I have previously wrote on this board that we used the Spare A/D input but I was wrong. We were using that as the two-step input. It's been a while. :) I know UEGO won't work because the ECU is programmed for 0v=10:1 and 5v=20:1 which is a different scale than you're showing. The O2 setting will probably just log in mV too if I remember right.

You are having the same issue others have with the voltage not reading correctly when logged. All I can say is that it worked correctly for us. Only thing I can think of being the issue is that there is a ground offset causing the issue. Innovate is notorious for these issues and their instructions are very explicit on how to properly ground the devices. Usually when this happens though you see a variance of tenths of a point AFR and not full points.

Another thought is that your WB isn't outputting in a linear fashion. Does the AEM output in a curved fashion? But if the manufacturer is giving a linear equation then it should have a linear output.

Claudio might have more insight or might be able to run it by one of the engineers for a quick answer.

Thanks for the response, Mr. Ludwig. I did run across your post that you mentioned, when I was searching earlier. This got me thinking about my spare A/D input, and why it was flatlining. Just for fun, I was going to ground the ground wire, associated with the spare A/D, to see if that would allow the red/black wire to start "seeing" the voltage applied to it. Other than that, I am not sure why it flatlines. Even in General mode, it should still record a voltage, shouldn't it?

The thought had crossed my mind, about the grounds. I do know that I am grounding the WB controller, on the same terminal as my E6X is grounded to. This is actually the terminal on the firewall, that the transmission is grounded to (S4 TII btw). For redundancy, I could run a wire from the terminal, to my battery, behind the passenger seat.

The interesting thing, is that what I read for mV output from the WB, using my voltmeter, is not what the E6X is recording, when attached to the O2 sensor input. Now, maybe this is where I am screwing up... in the E6X datalog setup, I am choosing Air/Fuel, when I am putting the signal from the WB, to the O2 input on the E6X. I do not reacall seeing any other selection in the choices for the datalogging, for the O2 input.

One last item... my WB controller is right beside the E6X, in my glove box. I took my 0-5 output from the WB, and tied it into the O2 input, right at the Haltech unit. I didn't see this as being a problem at the time, but maybe it is?

According to the literature for my WB, it is outputting a linear 0 - 5 volts. Also, the AFR's I am seeing, on it's software, are in line with what I would expect to see. It is using the same 0 - 5 volt signal, to display an output.

Thanks for the help!