LML Will not build over ~22PSI of boost

[RADustin]

long shot-

I found these 4 tables- that are all in line with each other. Left two are definitely temp based(I am converting K to C for ease). Right two I'm not sure.

Not sure about y axis on any.

The table data I am multiplying by .01 as this is typical-ish of N75 maps and EDC ECMs.

Do any of these values look 'correct' in any way?

[GMC-2002-Dmax]

Without the A2L or a Damos its all just a guess.

I found over 1000 tables with Winols and I know that many of them are tables that I could probably use, they are all grouped in sections in the code, but without a way to follow the routines for lookup adresses within the code its not easy.

I need a treasure map and all I have is a puzzle with no picture on the box.

I have been looking for an A2L or Damos for over a year for this EDC17 ECM.

Tony

[RADustin]

I can understand that. Context clues can typically narrow things down quite a bit in a hurry so its not always a complete guess. Just tossing it out there.

I still have yet to get this stuff to load correctly in IDA. Frustrates me.

[Chavez91]

I still have yet to get this stuff to load correctly in IDA. Frustrates me.

Working on this also. Its a PITA

[Dmaxink]

You guys seeing a consistent grams/sec it's happening at or a specific boost number? If someone can get me a trend I will try digging hard into the code. Need some type of number to go off if though that would seem somewhat constant.

Thanks
Kory

[Mitco39]

Kory,

At a specific power level it seems directly tied to the MAF. However when you turn up the power it seems to start sucking more air and allowing for more boost (all the while the turbo sits in its open position). However my thought is on it that the ECM is trying to limit air (or maybe its a simple as just limiting boost) by opening the vanes to stop itself as much as possible. I have noticed like I mentioned that maxing out the efficiency and compressor map tables will allow the turbo to close up to about 30% under load. Still not where it should be IMO but its much better.

[DURAtotheMAX]

Is calculated turbine shaft speed a valid PID in the ECM?

What is the most boost that someone is running on a fixed-geometry LML? What about on a twinned LML? Does the ECM try to limit boost by fueling in those cases? (where it doesnt have any/much control over vane position)

Just for grins...has anyone tried setting B1205 to "disable"? Like, even if you're still running a VGT on there, see what happens when you turn "off" the VGT controls?

Try messing around with the MAF sensor scaling and/or VGT solenoid scaling?

Is it RPM related? IE, if you command the TCM to hold a lower gear and roll into it without downshifting, does it still limit boost?

It would be interesting to build a little MAF fooler with a knob on it, and then do a WOT run, and as soon as the vanes drop to 0%, dial back the "MAF reading" a bit and see what the vanes do.

Or build a MAP sensor fooler, and see if that has any effect on vanes...

[Mitco39]

-I believe the most is Tony in this thread, he said hes making 32#s but that is still at or around 0% Vane POS. I have seen upwards of 28#s sitting at 30% vane. However this is on a full out tune with using as much fuel as the CP4 will supply.

-I have turned B1205 to disabled and the vanes will sit at 50% which yes allows for more boost up top but it also affects your spooling and no more turbo brake. Not really a fix at all.

-I have messed with the airflow tables, but not the raw MAF scaling tables. Never touched the VGT solenoid. I believe these might switch it up but it would just be masking the actual issue.

-It seems to limit boost no matter what the rpms in my experience.


Easier than making a maf fooler is just unplug it and remove the codes. See how the truck responds. I have not tried that myself yet. One could also try the MAP sensor fooler, that might put you in the right direction as to what is limiting the turbo.

[GMC-2002-Dmax]

I did a fully deleted, fixed vane, not vvt twinned with a exergy CP3 conversion and it fuels just fine.

I have a 750 mile drive home tomorrow, I will try to pay attention but even on a stock tune in my truck at WOT/25 PSI BOOST it will go to 0% for actual vane position.

[Dmaxink]

-I believe the most is Tony in this thread, he said hes making 32#s but that is still at or around 0% Vane POS. I have seen upwards of 28#s sitting at 30% vane. However this is on a full out tune with using as much fuel as the CP4 will supply.

-I have turned B1205 to disabled and the vanes will sit at 50% which yes allows for more boost up top but it also affects your spooling and no more turbo brake. Not really a fix at all.

-I have messed with the airflow tables, but not the raw MAF scaling tables. Never touched the VGT solenoid. I believe these might switch it up but it would just be masking the actual issue.

-It seems to limit boost no matter what the rpms in my experience.


Easier than making a maf fooler is just unplug it and remove the codes. See how the truck responds. I have not tried that myself yet. One could also try the MAP sensor fooler, that might put you in the right direction as to what is limiting the turbo.

Unplugging the MAF resorts in a 50% vane default.