Skipping/spotty data in logs -7747 TBI

[Cadmaro]

Would anyone mind helping me out with what i am doing wrong in these logs? It seems like it only logs a frame of data every few seconds so it completely misses entire WOT runs. 1990 Chevy truck, 355 vortec head TBI, 7747 ecu and using Tunerpro RT with $42-1227747-V5.2.adx. Using ALD cable made from amazon FTDI USB cable following instructions of of one of the GM tuning forums but don't remember which one. I have uploaded a couple logs for reference but am really lost in what the issue is. Driver settings? Settings in ADX file? Settings in Tunerpro?

[steveo]

the 7747 is a 160 baud aldl, those things spit out data as fast as they can, which is not fast. if you look at how much data the thing is cramming in one message... you can see why you're getting one 'message' per 1.2-1.3 seconds or so

if you want high rate logging you need a different ECM plain and simple, it's not your serial interface, it's your ECM

the only way to speed that up is to flash a new bin that is reconfigured to spit out a much shorter message (say just RPM, MAP, O2, TPS) that could more than double your logging rate which could be like a half second per message, that may be fast enough to accomplish your goals

[Cadmaro]

very interesting idea, is reconfiguring the BIN to only spit out the necessary info possible with TUNERPRO or would it be more involved than that? that seems like it would be the most ideal option for my current situation if it is actually doable.

[steveo]

it requires reconfiguring your bin....not sure if your XDF file has documented the logging parameters.

and then you need to reconfigure your ADX to match the new data layout.

it's doable but the difficulty level depends on your computer knowledge as well as the available parameters in your XDF, or if you can find a disassembly of your ECM. can be pretty advanced stuff

[Cadmaro]

Well, that sounds above my current knowledge/skill level when it comes to bins and other tuning files. Currently using $42-1227747-V5.9.3.xdf from this forum and don't know how or what to change so I will leave it alone. I got frustrated trying to figure out the tune on this truck so I am currently working with a professional tuner through email so I will see if that is within his scope of knowledge to change. Thank you for the idea though! If that doesn't work, it looks like a 7427 or EBL flash swap will be my only option. Real shame this thing doesn't log like my 24x/411 swapped Lt1 does! lol

[steveo]

even the original LT1 logged at a very useable rate

you know with a slow logging rate you could easily just change how you analyze log data
take lots of passes and do averaging and proper analysis and you will eventually catch all the 'in between' data points

another option for that old thing is to have EBL flash installed in it, it'll take that junk old ECM and hack it into a super ECM, screaming fast logging...

[Fast355]

even the original LT1 logged at a very useable rate

you know with a slow logging rate you could easily just change how you analyze log data
take lots of passes and do averaging and proper analysis and you will eventually catch all the 'in between' data points

another option for that old thing is to have EBL flash installed in it, it'll take that junk old ECM and hack it into a super ECM, screaming fast logging...

Cheaper, readily available option is repin to a 7427. They run better anyway.

[PlayingWithTBI]

even the original LT1 logged at a very useable rate

another option for that old thing is to have EBL flash installed in it, it'll take that junk old ECM and hack it into a super ECM, screaming fast logging...

This^^^ The EBL has the capability of updating the log up to 17 Times/Second.

[dave w]

Would anyone mind helping me out with what i am doing wrong in these logs? It seems like it only logs a frame of data every few seconds so it completely misses entire WOT runs. 1990 Chevy truck, 355 vortec head TBI, 7747 ecu and using Tunerpro RT with $42-1227747-V5.2.adx. Using ALD cable made from amazon FTDI USB cable following instructions of of one of the GM tuning forums but don't remember which one. I have uploaded a couple logs for reference but am really lost in what the issue is. Driver settings? Settings in ADX file? Settings in Tunerpro?

Fuel Rich / Lean summary from the combined .csv files in post #1

BLM Averages.JPG

[Fast355]

Fuel Rich / Lean summary from the combined .csv files in post #1

BLM Averages.JPG

That 51 has to be a random glitch in the data. That is well outside the limit of the BLM adjustment possible in the ECM.

The trend I do see is overall it is lean.

I datalogged these old ECMs with WinALDL back in the day. I really like the spreadsheet approach to the gathered data and the filtering options that could be toggled through. When I ran 7747 and 299 ecm back 2 decades ago, I datalogged for a 100 mile trip each way nearly every weekend for a whole summer to get things right. I made adjustments after each trip. After 3-4 trips I had it running pretty good. After 15 trips it ran pretty flawlessly. The EBL Classic came out not long after. I got one as a Beta tester before they were released to everyone. The file that RBob ran has 305 LG4 on ran better than the tuning I had been working on out of the box. I will say our engines were almost identical and we both had 350 injectors though. I threw the EBL into it, flashed the base LG4 file, my engine fired right up, started a datalog and threw it right on the highway. Engine ran smooth as silk and managed 19 mpg on that trip running 70-75 mph. Did not realize until later that lean cruise was enabled and because of that got very little in the way of BLM data that run. The EBL code just ran the engine better than the GM code. I noticed the same thing with the later 7427 type PCM as well. They just run better out of the box and the data stream from both gathers much more data in a shorter drive.

[Cadmaro]

Interesting points folks. I will look into the 7427 and EBL opinions a little more eventually but for now I'll probably try to get it as close as possible with the current ECU. If I get to a point where I want to switch, is there way to transfer my current tune to either of them as a base to start with? I know the tables will be different but wasn't sure how much could be "copy and paste" between the different options

[steveo]

doesn't take much effort to migrate over your fuel and timing no matter what you choose, but you will want to do some fine tuning after.

if the tables are different configurations (different columns and rows, different sizes) my tablehack tool is excellent at preserving the shape of a 3d table in different formats. that's one of the main reasons i wrote it.

[dave w]

I'll probably try to get it as close as possible with the current ECU.

Excel is helpful, not necessary. TunerPro RT History Tables provide good tuning information.

TunerPro RT Spark Advance.jpg

TunerPro RT BLM History (Fuel).jpg

[steveo]

problem with history tables in my eyes is lack of filtering

'blm history' is not a great metric unless you can drop events with power enrichment, or when not in closed loop, etc. more advanced tools can also filter out like TPS delta so transitional events disappear. it's also nice to add short term trim with long term trim and average that for better results,

the nice thing about excel analysis (and tools like my tablehack and trimalyzer which were designed to do the same thing but faster and with less skill) is you can feed them literally weeks of logs and filter out the data that doesn't matter, and get some really useful data

good engine analysis comes from averaging a ton of log data

[dave w]

problem with history tables in my eyes is lack of filtering

'blm history' is not a great metric unless you can drop events with power enrichment, or when not in closed loop, etc. more advanced tools can also filter out like TPS delta so transitional events disappear. it's also nice to add short term trim with long term trim and average that for better results,

the nice thing about excel analysis (and tools like my tablehack and trimalyzer which were designed to do the same thing but faster and with less skill) is you can feed them literally weeks of logs and filter out the data that doesn't matter, and get some really useful data

good engine analysis comes from averaging a ton of log data

I agree. There are:
Good - Tuning Tools
Better - Tuning Tools
Be$t - Tuning Tools

There are:
Good TBI ECM's
Better TBI ECM's
Be$t TBI ECM's