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Old 08-15-2018, 06:13 PM
  #16  
Lizard928
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Hello Marti,

In some versions of the software you can control where the NBO2 sensor is active and being used.
Otherwise, the system auto disables that feature when the MAF rate exceeds a set point, or when the WOT switch is engaged.
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Old 08-16-2018, 07:33 AM
  #17  
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Originally Posted by jcorenman View Post
The real-time adjustment is the "O2-adjust" value shown in Sharktuner, and the long-term average is saved as an "O2-adaptation" value. (Two values, actually). For example, if the real-time O2-adjust is moving around between say +6 and +14% (i.e. adding an average of 10% more fuel), then the O2-adaptation values will gradually change to +10% and the real-time O2-adjust will then be moving between -4% and +4%. As the MAF ages over time then it tends to read less airflow, and the O2-adaptation value will trend more positive, to the max of +20%.

Outside that shaded area the O2/fuel loop is shut off (i.e. the LH is running open-loop), with the fueling determined by the map values alone (plus O2-adaptation).
Is there a comprehensive explanation somewhere how the O2 adaptation system works? Is LH saving two O2 adaptation values globally or two per fuel map cell? Are those applied globally even when in open-loop mode and/or outside the designated closed loop cells? Does the O2 adaptation system get messed up somehow if the designated closed loop cells are tuned to something else than 14.5:1 AFR in the “cruise” fuel map?
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Old 08-16-2018, 02:46 PM
  #18  
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Originally Posted by ptuomov View Post
Is LH saving two O2 adaptation values globally or two per fuel map cell? Are those applied globally even when in open-loop mode and/or outside the designated closed loop cells?

They are global and applied everywhere. The primary purpose is to compensate for aging MAFs which would contribute an error everywhere.
Originally Posted by ptuomov View Post
Does the O2 adaptation system get messed up somehow if the designated closed loop cells are tuned to something else than 14.5:1 AFR in the “cruise” fuel map?
It can, yes. The NBo2 sensor only knows stoich (14.7 AFR or whatever), so that's where the cells in the "O2-adjust area" are are going to wind up (with O2-sensor enabled in Sharktuner). And if it takes a big fuel adjustment to get there, then that adjustment-- over time-- becomes part of the adaptation value. In reality this is only an issue for cells where the engine spends time. I excluded the lower-left (high-load/low-RPM) cells but that's not really a concern, because those are transitional (starting off in first gear for example). What's important is that the cruising-down-the-highway cells are all tuned to match the 14.7 AFR that the NBo2 sensor reads.

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Old 08-16-2018, 02:58 PM
  #19  
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Originally Posted by jcorenman View Post
They are global and applied everywhere. The primary purpose is to compensate for aging MAFs which would contribute an error everywhere.

It can, yes. The NBo2 sensor only knows stoich (14.7 AFR or whatever), so that's where the cells in the "O2-adjust area" are are going to wind up (with O2-sensor enabled in Sharktuner). And if it takes a big fuel adjustment to get there, then that adjustment-- over time-- becomes part of the adaptation value. In reality this is only an issue for cells where the engine spends time. I excluded the lower-left (high-load/low-RPM) cells but that's not really a concern, because those are transitional (starting off in first gear for example). What's important is that the cruising-down-the-highway cells are all tuned to match the 14.7 AFR that the NBo2 sensor reads.
That makes sense and also partly explains why the WOT fueling map exists in the first place, in addition to the algorithmic acceleration enrichment. The WOT fueling map is added only in the conditions under which the o2-loop doesn't run, so it's safe.

In any case, I think it's underappreciated by the tuning public that the "cruise" map must be tuned to lambda = 1 in the cells in which the o2-loop is ever allowed to operate if one wants to run the o2-adaptation.


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Old 09-26-2018, 04:56 PM
  #20  
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I seem to have a fault with the WB02 sensor which I am hoping someone can identify.

It has started to read maximum lean after a short time from start up without changing the map.

Literally the A/F mixture on the ST will look a little subdued around the stoic number, then start fluctuating between rich and stoic before just shooting straight to full lean 18.99.

I observed yesterday that it did this for the first few minutes until the engine had warmed up and then seemed to work fine but today it just registers full lean even after the engine is warmed up. If I stop the engine and restart I get it registering 9 while the engine if off and then with the engine started I get a small fluctuation for a few seconds around stoic before shooting to full lean

Does anyone know what this is?
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Old 09-26-2018, 04:57 PM
  #21  
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Faulty sensor on the WBO2 would be my guess. How old is it?
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Old 09-26-2018, 07:17 PM
  #22  
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It’s about 3 years old and has about 2k miles in it
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Old 09-26-2018, 10:39 PM
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Is it reading correctly elsewhere? It could also be a misfire dumping a cylinders worth of unburnt air into the exhaust.
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Old 09-27-2018, 05:58 PM
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def faulty sensor.
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Old 09-28-2018, 11:22 AM
  #25  
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Marti,

Did you ever run the motor with the WBO2 sensor installed but not powered up by any chance?- I understand they do not like that at all- a shot to nothing as it were [however unlikely].
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Old 09-28-2018, 07:03 PM
  #26  
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I am going to go for a change in the sensor as per Colin's suggestion. If feels electrical to me as there is no change in engine note when the sensor goes to full lean which does not correlate.

Strangely it was working yesterday after revving it a few times so I will see if it clears, maybe clogged or something.

I also took the time to run a CR check while changing the plug leads (they were deteriorating) just to check for any anomalies - all cylinders were 150 psi within about 2 psi of each other so all normal.
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Old 09-29-2018, 12:00 AM
  #27  
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Take out the sensor, heat it up with a small handheld propane torch (not too hot that will totally fry it).
Then do a fresh air calibration and see if it works again....
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Old 09-29-2018, 03:10 AM
  #28  
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^^What he said.

Except pee on it first, Bear Grylls would.
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Old 09-29-2018, 10:39 AM
  #29  
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Originally Posted by Marti View Post
I also took the time to run a CR check while changing the plug leads (they were deteriorating) just to check for any anomalies - all cylinders were 150 psi within about 2 psi of each other so all normal.
You numbers are 30 - 40 psi lower than what I've consistently seen on stock S4 engines.

Is the engine modified?
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Old 09-29-2018, 11:22 AM
  #30  
Marti
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Originally Posted by SwayBar View Post
You numbers are 30 - 40 psi lower than what I've consistently seen on stock S4 engines.

Is the engine modified?
Yes, the engine is running Colin’s cams
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