Just went from OLSD to CLSD, some questions

Enlighten me on the CL mode. I've been NBless for 3 years now and am drawing a blank

Essentially, you can set different switch points for different grams/cyl. It's all under the Engine>Fuel>O2 folder IIRC.

muchas gracias. i feel much less a tard now

Quote:

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Originally Posted by TAQuickness

Wouldn't it stand to reason that if you disabled CL fueling the NB's voltage should draw a straight(er) line for a given AFR? (Kinda like when NB's peg at 800+ mv at WOT)

If so, you could monitor AFR with the WB and associate stoich to the respective NB voltage. At that point you would know which way to move your NB switch points.

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Trust me to overly complicate matters, but you are dead right. That would be much easier. Like you TAquickness I havent had a narrowband in my car for a few years now so I am basically running on theory.
Cheers Mick

Ok, I moved my switch point from 450 across all CL modes to 425.

My trims did move in the correct direction (down). They all look pretty good besides a few cells in the matrix. The cells that look wrong to me are in the 1400-2200 column, and in 37-57 kPa, and 57-77 kPa cells. I took these screen shots after ~45 minutes of driving, during 2 ignition cycles. Not sure thats really enough time to settle out or not, or hit every operating condition required. But here they are.

Bank 1
http://i93.photobucket.com/albums/l5...-8-08LTFT1.jpg

Bank 2
http://i93.photobucket.com/albums/l5...-8-08LTFT2.jpg

The cells that look off to me are large positive values, meaning that they are adding fuel. However if I look at a log of driving at those conditions I see that the AFR is still slightly rich, and the BEN is of average 98% at those conditions (14.68 is the command at those conditions that I inspected in the log).

Perviously (before I changed from OL to CL, I saw BENs of 0.995 in those cells in the map. If this is the case, then when I switch to CL, and the long term trim becomes approximately +10%, I would expect the mixture to be VERY rich, about a BEN of 0.90, but that is not the case. I see a BEN of 0.98 at thos conditions in CL. At this point I don't really understand what is going on.

Can you post a log with both 02 sensor voltage pids, wideband pid & dyncylair.dma as well as the usual rpm,ect,iat etc to look at. Make sure you are in open loop though as TAQuicknesses way should be quicker.

What is the grams/cyl range for those cells? You need to log actual AFR averages based on grams/cyl. Then, you can translate those areas that are performing incorrectly into what CL mode it's in. Then, you'll know where to adjust your switch point. Make sense?

I switched my tune back to OLSD and logged WB02, NB02 voltage, short term fuel trim, load (g/cyl), and many other standard parameters. Then I took the data and sorted it so I could put it in the LTFT matrix.

I am currently running 425 mV as the 02 switch point across the board.

You'll see 5 values in each cell in the matrix.
1. GM.DYNCYLAIR_DMA (g/cyl)
2. WB02 (AFR)
3. Short Term Fuel Trim (%) - NOT ACTIVE
4. Narrow Band 02 Voltage Average (V)
5. Long Term Fuel Trim (%) - NOT ACTIVE This was logged yesterday from when I was in CLSD.

I'm not sure why the AFR data isn't dead on. I did some filtering, but I guess not enough, and I wasn't as steady state as I was when I did the VE tuning. This was taken from a ~25 minute long work commute. I filted out low coolant temp data, and data with throttle movements greater than a threshold.

My real issue was with the parameters in the 1400-2200 rpm cells with 37-57 and 57-77 cells. The LTFT was very large in those cells. If I updated the switch points for the loads (CL mode) that correspond with those cells I'll be changing other cells as well, right? Also, table B4104 looks weird. The x-axis uses GM.DYNCYLAIR_DMA and calls the units in (grams/second). I was under the assumption that the units are in (g/cyl). The same parameter is used in the spark table and it calls the units out in (g/cyl). The range is 0-320 in the CL Mode table, which isn't anywhere near the actual DYNCYLAIR_DMA range ~ 0-1.20. What is going on there?

http://i93.photobucket.com/albums/l5...LTFTMatrix.jpg

From this data, where do I go from here?

I have also attached my tune and log file that I created this data from.

Kevin,
What did you use to create the matrix above?

I created that in excel, however I just did it manually. It was actually pretty much a pain in the ass since the cells aren't the same size.