NefMoto

Technical => Data Logging => Topic started by: Jason on May 22, 2011, 10:55:23 AM



Title: Wideband logging using rear O2 sensor inputs?
Post by: Jason on May 22, 2011, 10:55:23 AM
One thing that I've found irritating is that I have no way to log my LC-1's against RPM.

Thinking out loud here but I am wondering if this is possible by wiring the analog outs from my Innovate LC-1's...  Basically disable heater diagnosis, disable secondary correction, and then include the rear O2 voltages (read: wideband analog out) in my logging?

Am I wrong in thinking that the rear O2 inputs are 0-5v?



Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: julex on May 22, 2011, 05:05:13 PM
One thing that I've found irritating is that I have no way to log my LC-1's against RPM.

Thinking out loud here but I am wondering if this is possible by wiring the analog outs from my Innovate LC-1's...  Basically disable heater diagnosis, disable secondary correction, and then include the rear O2 voltages (read: wideband analog out) in my logging?

Am I wrong in thinking that the rear O2 inputs are 0-5v?



I don't know about innovative (since I filed is as crap after reading specs and stuff needed for me to get wat I need) but zeitronix can be wired directly to tach input and log RPMs.....


Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: Jason on May 22, 2011, 07:17:11 PM
It can...  but I have to buy yet another box.  And my under-dash already looks like a Rube Goldberg disaster so I'm hoping to avoid adding more wiring.

Today I ran a wire from the LC1 analog out to the post cat O2 harness, and used an old sensor plug.  I observed that the ECU isn't capable of sensing anything > 1v.

So, I set the LC-1 to output .05v for lambda .5 -> 1.5... ECU sees .049v
I then set the LC-1 to output 1v for lambda .5 -> 1.5... ECU sees .96v

Then I set the LC-1 to output .05v for lambda .5 and 1v for lambda 1.5

So, assuming the LC-1 is linear as people say, I decided I can just use a linear interpolation function for excel when I look at my logs to give AFR reference.

I measured the following voltages in the ECU when the LC-1 read the following AFR's:

AFR: Voltage
18.9 .770v
18.4 .740v
14.3 .485v
11.1 .285v


Using linear interpolation, I interpolated the AFR by measured voltage


AFR: Voltage Interpolated AFR
18.9 .770v 18.98
18.4 .740v 18.49
14.3 .485v 14.37
11.1 .285v 11.14

I am not going to use it as gospel, but it's interesting how it seems to be pretty close.


Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: Rick on May 23, 2011, 03:13:19 PM
I use the zeitronix to log RPM, AFR and boost as the ECU is no good with its 1.5 bar boost limit.  I log at the same time as ECUx :)


Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: Jason on May 23, 2011, 03:31:51 PM
I had an interesting thing happen this morning... I was datalogging, and the car fell on its face after shifting to third gear.  Hard.  It was rich to 8:1 or so.

I looked at the log, and it definitely went pig rich.  CF's also went through the roof, which I thought was weird since it wasn't pinging.

Interestingly enough the AFR log from the wideband input looks exactly like KFLBTS_0_A at full load.  So I'm wondering if the wideband input is triggering component protection via TABGBTS? 

Here is the AFR log and KFLBTS_0_A

"calculated" is the default ECUx parameter logged in the "typical" egp floating around.  "Actual" is the wideband logged over the B1S2 input, converted to lambda using linear interpolation.

(http://i.imgur.com/EphBA.png)

(http://i.imgur.com/8eShV.png)

I'm wondering if I missed a codeword somewhere?  Can the post cat O2 even be used to trigger component protection???


Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: nyet on May 23, 2011, 03:37:02 PM
Simplest explanation is dying EGT.

Didn't see if you logged it...


Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: Jason on May 23, 2011, 03:47:41 PM
I did... they are 1733 the entire time...

Knock voltages were lower than normal.

Correction factors usually around 3, went up to 9.

Overall timing fell....  and of course engine load was not matching specified load.


Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: nyet on May 23, 2011, 03:51:40 PM
Post up the log, i'll take a look.


Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: Jason on May 23, 2011, 03:57:09 PM
see attached...



Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: nyet on May 23, 2011, 05:13:08 PM
see attached...
Please send an exported csv so I can view it in ecuxplot :)

Not a fan of .xls, I can't parse it into anything useful.


Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: Jason on May 23, 2011, 05:14:24 PM
I will post up when I get home since my datalogging laptop is in the car :)


Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: Jason on May 23, 2011, 05:22:02 PM
I will post up when I get home since my datalogging laptop is in the car :)

Actually, try this, I parsed it back over.  I use excel because I leave the log running and use conditional formatting to identify where I've been WOT.



Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: nyet on May 23, 2011, 05:36:24 PM
Wow. You're right. The only explanation I can see is your wideband input is confusing the ECU, even though it is only on the rears.

Your actual AFR does seem to be following the req. pretty well. Like you said, something is making the ECU want to dump fuel, but I can't figure WHAT except for your rear O2 reading.

I'm guessing it thinks that bank is running super lean .. i forget the posters name, but he said the ECU would do that if it saw lambda > 1 on the narrow bands. I guess it also does it due to the REARS.


Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: Jason on May 23, 2011, 06:35:37 PM
I unplugged the LC-1 and plugged the old sensor back in before I left the office.  I cleared the DTC's to reset the ltft's and whatnot.

Fuel dump went away.  It's about 105 degrees out so these logs are kind of funny.  I attached one with some pretty neato IAT's after sitting in stop and go for a while without any air over the IC's.

nowb.csv shows a third gear pull

loliat.csv shows a 2-3 pull with IAT's hitting 150+

This file is the same file I posted in the tuned files section (tony's Stage 3 + no lift shift antilag) with stock idle torque reserve and stock injector latencies, with KRKTE set to .0650.


edit:  I guess that lends the question, in order to get this to work, do I have to completely disable secondary correction?


Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: nyet on May 23, 2011, 06:39:16 PM
do I have to completely disable secondary correction?

My magic 8-ball says "most likely" at this point...


Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: julex on May 23, 2011, 08:25:55 PM
Is it in this thread or some other one where somebody posted a bit of info which indicates that O2 readings below certain voltage (extra lean) will trigger a routine in ECU to dump the fuel as an emergency measure.


Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: Jason on May 23, 2011, 08:27:06 PM
That would make sense as voltage drops with lambda.  I could flip the voltages around, so that rich = high and lean = low...


Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: ElementalVoid on May 23, 2011, 09:41:35 PM
Is it in this thread or some other one where somebody posted a bit of info which indicates that O2 readings below certain voltage (extra lean) will trigger a routine in ECU to dump the fuel as an emergency measure.

I think this thread is what you're thinking of:
http://www.nefariousmotorsports.com/forum/index.php/topic,524.0.html


Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: nyet on May 24, 2011, 01:38:15 AM
That would make sense as voltage drops with lambda.  I could flip the voltages around, so that rich = high and lean = low...

Yup. That should do it if that is the problem


Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: Jason on May 24, 2011, 11:35:14 PM
Well... it's not the wideband causing the fuel dump.  It happened twice today with the narroband connected... now I get to figure out what is causing it.. hooray!


Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: Rick on May 25, 2011, 10:18:36 AM
Cars with EGT sensors I set BTS protection exactly the same as LAMFA.  If things get too hot the sensors add the needed fuel.  Maybe try changing the BTS maps to see if it is them.  Is overboost related calibration ok, and no knock when this happens?

Rick


Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: nyet on May 25, 2011, 10:22:22 AM
I'm still thinking bad EGT sensors. This is a common problem and it doesn't always show up in logs.


Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: Jason on May 25, 2011, 10:41:58 AM
It's possible I guess... they have less than 10,000 miles on them though.  I need to switch back to my tune since this was on Tony's file with the antilag mods, and see if I hit it again.

Hopefully I will have time to look at it this weekend.  The overboost is likely due to the K16 hybrids and running Tony's K04 tune.

edit:  forgot to mention no knock.


Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: Jason on May 27, 2011, 11:31:43 AM
Woooo!  It's leaning out bigtime in third gear, but is around 11:1 in first and second gear.  Will fix and report back.


Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: IGA on April 04, 2017, 09:35:32 AM
So, finally is it the issue to connect Wideband to rear O2 sensor inputs ?


Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: BlackT on April 08, 2021, 05:59:59 AM
Any new input about this? I also want to log wideband on 2.7T
Is rear O2 good input?


Title: Re: Wideband logging using rear O2 sensor inputs?
Post by: prj on April 08, 2021, 06:19:31 AM
I always used it, never had issues.
I have an external lambda on the dyno, and the reading matches both on the dyno as well as in the log when using the same factor.