2008 LMM air-fuel ratio control / support problem

Hello dear fellows! I built a smokeless tune using mixture limits and it works good, but there is a problem. No matter how much I "lean" mixture, mixture limits I set ignored approximately for the first second after I push throttle hard. Seems like it uses different limits than these which available for editing first second after throttle was pushed.
I think there is a transitional air to fuel limit table which we do not see in EfiLive or similar hidden parameter. My question is how we could get access to that area? What else do we know about the problem I described here?

I contacted helpdesk with this issue and they closed my ticket number 2368-IPAF-1390 saying LMM is out for support. At the same time LMM listed on efilive.com as supported.

As I found, we have two problems instead of 1 here: not having complete access to mixture control and advertised LMM support seems like actually not supported or servicedesk does not proceed LMM support requests properly. I am trying to reach here management and other people who are competent in these two areas so we could combine our efforts in improving EfiLive product and it's support.

Regards,
Ed.

Did you modify table B0797? Maybe that is limiting you.

I tried different parameters for B0797 in the beginning and it was not quite clear what exactly it does so I left it stock. Can't remember details now, that was a long time ago. As far as I remember common believe that we have to lower these RPM (Fuel mixture limitation will only be applied once RPM is above this value. - EFilive says) (6000 default) to activate mixture control but my tests showed that is wrong and mixture control definitely activated below that setting so I was worried that works opposite way and left it stock. Can you enlighten me more on this setting please? I highly appreciate your response and you are making a very good point. I would be so happy to finally fix this!

How are you determining that the mixture limits are being ignored? Does I puff a small cloud or are you watching scan data? Is the vehicle deleted? What kind of power increase are you pushing for? I don't have really have personal experience on this issue, but just saw that table and wondered if you messed with it.

I also noticed on the file I was looking at that table B0794 is limited richer than the leanest points on table B0795. You could try changing table B0795 to all 1.3 Lamba or something and see if you still have the temporary unlimited scenario.

Just came home and verified B0797 table I have. It actually set to 600 RPM. And mixture limiting does work, no doubt in that. I tried it on max lean, when I push accelerator to the floor RPM barely go up and the truck can not shift into second gear lacking power. However I look at exhaust and it still does make small black puff if I press accelerator quick and hard enough. Also engine accelerates harder than expected first 0.5 second then goes back to expected lean. And if I slowly accelerate engine to higher RPM and then press accelerator to the floor the same story - black poof first 0.5 second then clear. Truck deleted, power decreased to about 280-300HP, exhaust pipe stays clear from soot like it is not deleted and it does not smoke even towing a heavy trailer uphill and at high altitudes too. I am very happy with the results, that is the lack of control over that 0.5 sec. issue what makes me frustrated overall. I have experience building custom carburetors, ignition systems, rebuilding and tuning diesel engine fuel systems and based on reviews was expecting much more complete control over ECU from EFIlive when was ordering it. And now they even say they do not support LMM anymore. We need some sort of advanced manual how to decode and tune ECU parameters not available from EFIlive user interface at least if they do not want work on making it complete.
Thanks a lot for your response!

So I found that tweaking the digital maf scale be more help in fine tuning smoke output at pre-boost intervals. The mixture table is a good start, but if you want it perfect, play with the maf scale.

Thought about that. Thought about tweaking injection pulse time also. The problem is that we can not tweak these parameters only for a second, there is no transient tables for that. It still could workaround the issue only in case if ECU takes injection parameters for that second out of some fixed tables not related to mixture tables we can edit. Then if we intentionally tweak air tables 1.5 times down or pulse tables 1.5 times down (slightly harder to do) and enrich mixture 1.5 times then resulting mixture remaining the same but their internal hidden tables are 1.5 times leaner now, what we want. If enriching for that second based on the same mixture tables we edit (ECU OS dividing numbers by 1.5 times lets say) then resulting mixture will always be adjusted after all our tweaks and result will not change. I can try it and report results here for others. I am just too disappointed and sick of it, that is why I still did not try it for myself. We need a proper solution, not a hack rising more issues in the future.

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Originally Posted by Krapovnitsky

Thought about that. Thought about tweaking injection pulse time also. The problem is that we can not tweak these parameters only for a second, there is no transient tables for that. It still could workaround the issue only in case if ECU takes injection parameters for that second out of some fixed tables not related to mixture tables we can edit. Then if we intentionally tweak air tables 1.5 times down or pulse tables 1.5 times down (slightly harder to do) and enrich mixture 1.5 times then resulting mixture remaining the same but their internal hidden tables are 1.5 times leaner now, what we want. If enriching for that second based on the same mixture tables we edit (ECU OS dividing numbers by 1.5 times lets say) then resulting mixture will always be adjusted after all our tweaks and result will not change. I can try it and report results here for others. I am just too disappointed and sick of it, that is why I still did not try it for myself. We need a proper solution, not a hack rising more issues in the future.

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I fail to understand how the mixture table, and skewing the maf to accomplish a smokeless tune is such a travesty? I've had zero issues using those tables together. It creates zero issues, there are no cons to doing it that way. There is no need for a transient table for underboost conditions. You can do it all with one table. Maybe its you not entering in the correct values.

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Originally Posted by Monster50iii

I fail to understand how the mixture table, and skewing the maf to accomplish a smokeless tune is such a travesty? I've had zero issues using those tables together. It creates zero issues, there are no cons to doing it that way. There is no need for a transient table for underboost conditions. You can do it all with one table. Maybe its you not entering in the correct values.

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I do not understand why you are keeping mention underboost conditions. While underboost condition obviously occurs when accelerator pedal floored fast enough that is not an any sort of issue here. The issue is again that when we press accelerator the ECU attempts to mimic how accelerator pump works on carbureted engines: for a short period of time it injects more fuel than calculated based on pedal position/requested torque/torque limits/mixture limits tables to get better throttle response. I want turn off that feature or at least limit that extra injection amount. I made another experiment. I skewed air mass table down 1.3 times and skewed mixture control table 1.3 times reacher so I have got the same final mixture limit I desire. And pressed accelerator pedal hard to the floor. Instead of black poof I saw white poof coming out of the exhaust pipe. Then ECU went into limp mode because air flow was below expectations. I reset the error and floored accelerator pedal again - only white smoke again. The test was incomplete because it is hard to judge based only on how smoke looks like at speeds close to idle. Just not enough air flow through the engine to create obvious visual smoke cloud. The worst black clouds I get when the engine is preboosted as much as I can and then accelerator pedal floored fast at speeds over 1500 RPM. Because it enters a limp mode quick I was unable to preboost it. But what I saw - white smoke instead of black - most likely proofs that it does not ignore mixture limiting function for a half of a second when accelerator pedal hard pressed but rather uses some sort of transient mixture limiting data for that period of time and ignores data tables and settings available for us. If that was just ignoring mixture limits tweaking air down would not change smoke color.

I do not get it why or how you consider tweaking MAF table issues free. That is one of the fundamentals data sources for many future calculations and we really want to see actual air flow, not a skewed because of that. How ECU is going to detect faulty MAF sensor if the MAF table is skewed? I was unable to find any provisions to fix that issue. How ECU is going to calculate properly HP, torque and soot mass, EGR flow for not deleted trucks? I did not find how to fix that issue. These are obvious issues we most likely can not solve having incomplete editing access and there are may be much more hidden issues.

You are right, I may do something or everything wrong but I did not see any at least workaround solution yet from other tuners as well. The issue is still there and I am ready to swear I am not the only one who experiencing it (probably the only one who cares based on my forums study).