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Did Some Data Logging with TunerPro R/T

1-ton

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I finally got around to doing some data logging with my TunerPro software. The data logging is on a GM 350 TBI crate engine with about 6,000 miles on it. It has a small RV cam, bored out TBI with the ultimate mods, and adjustable fuel pressure regulator set at 13-PSI. The ECM is a stock chip.

I have a video of the data logging session. If you open the video up to "Full Screen" you should be able to see clearly. I do not understand a whole lot about what the data logging is showing. If anybody that knows more about it than I do could comment on what they see. From what little I do know it looks OK.

 

dyeager535

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A basic tuning tenet is that a BLM of 128 means the system is not having to add or remove fuel from the base programming. You'll never see 128 as a constant, but +/- a few under light throttle/light load conditions is a good place to be. BLM is only telling you whether the system is adjusting from the base data...it doesn't mean it IS running lean or rich, only that the system is correcting for that, if it's off the 128. Yours looks like it's pretty consistently on the rich side, and depending on what the settings are for the TBI programming, you might be bottoming out the adjustment...the system can only adjust for so much or so little fuel, the BLM's (and INT) will only go so far up or down, depending on the programming. Low BLM is rich, high is lean. Again, CORRECTING so it doesn't go rich or lean, not actually running rich or lea, as long as there is still room for the BLM to go up or down, respectively.

The value of being in the middle (128) is that if something changes (load, gas quality, etc) the system has room to adjust. If it's at the very end of the adjustment for rich or lean, the system can run out of room to add or subtract fuel. Obviously not being to add fuel when needed can be disastrous.

Personally I like the .CSV exported spreadsheet view, so I can see things like TPS, load, vehicle speed, BLM etc., without the numbers constantly shifting, as they do with the dash. That's just me though. I recall EagleMark liked to use the graphing feature.
 

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Personally I like the .CSV exported spreadsheet view, so I can see things like TPS, load, vehicle speed, BLM etc., without the numbers constantly shifting, as they do with the dash. That's just me though. I recall EagleMark liked to use the graphing feature.

I tried to use the "Export Log File" utility in TunerPro, but after I converted the log file to .CSV the file still will not open in Excel.
 
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1-ton

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The value of being in the middle (128) is that if something changes (load, gas quality, etc) the system has room to adjust. If it's at the very end of the adjustment for rich or lean, the system can run out of room to add or subtract fuel. Obviously not being to add fuel when needed can be disastrous.

My BLM middle seems to be 126. It bottoms out at about at just under a BLM of 105 trying to lean my engine out due to it running rich. You can see the TunerPro software flash red for a second trying to warn that it is out of adjustment trying to lean out for a rich condition. That seems to mostly happen right as I am backing out of the throttle.
 
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dyeager535

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I think it's generally normal to see a rich spike as you let off the pedal. As long as it's not staying rich. I assume TBI goes into some form of fuel cutoff/reduction based on vehicle speed and TPS.

I havent played around with tuning and datalogging much for awhile, I want to say there are two steps to getting it into a csv.
 

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I want to say there are two steps to getting it into a csv.

These are the steps I tried when using TunerPro's "Export" utility.

Menu: Acquisition>Export Log File> search file> select log file>open>convert to CSV>Dialogue: This file already exists. Do you want to change it? Click: YES.

I then look at the file and it has two file extensions...XDL and .CVS, but still will not open in Excel office app.
 

dyeager535

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If I get time let me try tonight and see if I can figure out how I've done it. You can try emailing to me if you like, same username @ Yahoo. Just to make sure it's not some weirdness with your computer, if you havent already tried that.
 

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If I get time let me try tonight and see if I can figure out how I've done it. You can try emailing to me if you like, same username @ Yahoo. Just to make sure it's not some weirdness with your computer, if you havent already tried that.

One thing I am going to try is create a new log file and "Export" (i.e. change) the file to the .CSV file extension before the log file is "Imported" into the TunerPro app that allows you to do a play back of the data logging session that was just created.
 

dyeager535

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I just went in to play with TunerPro, and without being connected to the ECM, I'm pretty well lost. It looks like you have to have/make an ADS or ADX file to have a "dash" (my dash is a blank window), so while I can load a data file and play it, I can't see anything other than the mark moving to indicate the file is progressing as it plays.

But this jogged my memory. When I datalog I record, then stop, "save file as" IIRC, then through the menu export that file as csv. Or so I recall. I just stuck with what worked for me, but without actually running through the steps, which isn't possible if you can't datalog, I can't recall the exact procedure.
 

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The other advantage for keeping the BLM numbers close to 128 is that while the motor is warming up, it’ll drive a bit better since the computer uses the 128 fueling until it goes closed loop.

My data logging favorite is just to display the BLM spreadsheet chart in Tunerpro with data filter set to “average”. Then I just take a picture of it with my phone and go back to the computer to adjust the numbers. Don’t have to fool around with exporting file in that case. It also matters “how” you drive in that case. I avoid stomping on the throttle or accelerating very fast so the averages aren’t skewed. And I try to find a hill to go up to get the engine load higher.

I’m not an expert, but saving file and playing it back is a little helpful in finding other issues like why knocking count might have been recorded so you can make timing adjustments, but not so much for fueling adjustments unless you have a specific issue you’re trying to work out.
 

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My data logging favorite is just to display the BLM spreadsheet chart in Tunerpro

Where do you find the BLM spreadsheet? It looks like the "Tables" spreadsheet is just .BIN file info, and not what was recorded during the data log session.
 

JoshHefnerX

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Haven't messed w/ TBI stuff. But in LS world 2-3% adjustment is considered 'spot on' 5-6% is 'ok' and 8% or more is needing some adjustment.
 

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Can you tell by the video I posted if I am in that 2-3% range?

105/128= .82

That means it’s 82% perfect, which is 18% error. I’ll have to open TP and take a screenshot to show you where the table view is. 105 is kinda rich, but if it’s only for a second during transition, I don’t think it’s a big deal.
 

1-ton

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105/128= .82

That means it’s 82% perfect, which is 18% error. I’ll have to open TP and take a screenshot to show you where the table view is. 105 is kinda rich, but if it’s only for a second during transition, I don’t think it’s a big deal.

Kool. Thanks.
 

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Going off memory: you really need to record the BLM and correction tables. The short term correction is what reacts to the O2 sensor and adjusts the BLM cell.
- O2 reads lean
- Correction cell moves above 128, which causes BLM to follow above 128
- BLM is a multiplier that then enrichens the air/fuel mixture
- once O2 reads correct mixture, correction cell stabilizes at 128 and BLM is no longer adjusted (but remains at new number)
This tells you that the computer is using BLM to adjust to a lean condition by adding to the mixture.

So now record the BLM tables and divide the BLM in each cell by 128 and subtract from 1 to get your adjustment factor for that cell.
In your example, if you are recording a 105: 105/128=.82 1-.82=.18 or 18%.
In your air/fuel table, reduce the number in that appropriate cell by 18%.
Now do this in all your cells that need adjustment.

If you are universally seeing low BLM numbers, you may want to start by lowering your fuel pressure and do another run.
 

Keitha

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One other word of caution: 105 may be the limit the ECM uses. It may be running richer than that, but BLM won’t adjust past 105
 

bp71k5

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Here’s the pictures of the table you want. Sorry it took so long.

Show the table:
28DDB009-0D6F-481D-AD15-F45D8CB08C50.jpeg

Set the table to “history average”
14516C02-0B3B-45D6-9CB7-E4DE0027DA12.jpeg

Then drive around a while over some freeway, up some hills, etc making sure to speed up slowly and not stomp on the throttle. Try to fill in as many of the cells as possible, but no need to go crazy with it.

Once you get those settled between 120-135 you mess with other stuff as needed.
 

1-ton

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Here’s the pictures of the table you want. Sorry it took so long.

Show the table:
View attachment 305179

Set the table to “history average”
View attachment 305180

Then drive around a while over some freeway, up some hills, etc making sure to speed up slowly and not stomp on the throttle. Try to fill in as many of the cells as possible, but no need to go crazy with it.

Once you get those settled between 120-135 you mess with other stuff as needed.

Yes, I found "History Tables" over the weekend, and did some data logging with it. It looks like you cannot save History Tables when done with data logging. It looks like the only way to save History Tables is to do a screen shot, and then paste it to Word Pad or something like it. Then save that as a file. It also looks like History Table only shows the highest and lowest BLM's, which allows the mathematical equation you already did . It also has a History Tables that shows the BLM average.
 

1-ton

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If you are universally seeing low BLM numbers, you may want to start by lowering your fuel pressure and do another run.

I have an adjustable fuel pressure regulator that is currently set at 13-PSI. Do you think I should lower it?
 
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