View Full Version : LMM Timing/fuel Limited?
LBZoom
February 26th, 2011, 04:16 PM
Hey guys,
Going through a recent log from a 2009 LMM OS 28594 and noticed that when I play the log back the timing in the log doesn't correspond with my tables.... it goes from being too low, to being too high relative to what I'm supposed to be getting at that mm3 and RPM.... is it just a glitch in the logs?
Also, it's showing that my max timing was 18.8* it should have been several degrees more than that.
Another thing is that I'm commanding a max of 125mm3 of fuel and it showed in that same log that I was maxing out at 106.6mm3....another glitch? I've been through the tune several times and can't find any reason why it should be coming up short.
Thanks for any help!:cheers:
Is it possibly something in the trans? I guess we still can't read 2009 TCM's huh? I tried several times to upload the stock file even and it kept saying bootloader rejected, I have downloaded the most recent updates...
rcr1978
February 27th, 2011, 03:51 AM
It's from all the temp, altitude multiplier tables, pilot on/off. Thats just the way the LMM, LBZ are they are totaly different from LB7,LLY. Take a look at the torque reference tables theres lots of them pedal position & torque based fuel, there is also other torque limiters your just gonna have to dig through it. As far as the timing there is a couple of ways to do it, zero all multipliers to see that your getting what you want then go back through them and set to your liking, or just log and fudge the numbers in the timing table until they are close to what you want. There is the torque table in the trans but I'm not sure if it's really holding you back I would worry about the ECM first.
Dmaxink
February 27th, 2011, 06:14 AM
Easiest thing to do is create a map..say a actual timing map..once you have filled
Most of the cells in the map with +10 or so hits go back and compare actual timing throughout the whole table to what you were asking for...from there go in and look at the limiters and multipliers.. Like previous poster said..check out the limiters for the mm3... Feel free to also email the tune to me if your not secret about it and I can try and help you pin point it also. Cheers!
LBZoom
February 27th, 2011, 02:57 PM
Well, I've dug through all the tables as you've both suggested already....at that ECT, IAT, etc, it shouldn't be limited like it is. And another thing worth mentioning that I forgot, the timing goes from being too high, to being too low all in the same log....limiters don't flucuate like that from what I've seen, correct?
I'm quite familiar with torque referencing as I have an LBZ, and if you recall the LBZ wouldn't read from the 812lb ft row in "pedal position to desired torque" in OS 08128, it would only read from the 776lb ft. row, perhaps the LMM has a similar issue?
All MM3 limiters are set well above 106.6, and all torque limiters are well above what I'm commanding from my torque table.
I'm looking for a more specific answer from anyone who has ran into this issue before, and if nobody has had this issue that's fine I'll keep looking, but with all due respect the general answers about how I should look at limiters and such are the obvious, I'm not a beginner, although I realize that the LMM's are a different species. Thanks for the input guys I really do appreciate it I'll take the advice into account and keep looking!
Dmaxink
February 27th, 2011, 04:19 PM
k, post a log and lets go from there...
bondurch
March 25th, 2011, 09:04 AM
10225" Another thing is that I'm commanding a max of 125mm3 of fuel and it showed in that same log that I was maxing out at 106.6mm3....another glitch? I've been through the tune several times and can't find any reason why it should be coming up short."
I just want to preface that im beggining to have a better understand EFI live and how the tables work together, but this one has stumped me. From what I can see in my tune is that I should be maxing at 120mm3 but never see over 106mm3. If anyone has figured out why that would be great to understand.
Another issue that I have is from the Pedal Position to Desired Torque where I command torque values well over 1200 (1897 to be specific)on WOT, but when I go to Torque based fuel tables the Y-axis engine torque maxes at 1200. How does the ECM calculate the fuel volume?
Just when I feel I am starting to grasp the EFI live I get totally stumped.
DirtyMax03
June 3rd, 2014, 12:00 AM
Resurrecting an old thread here, but this was the most pertinent thread I could find regarding the issues I am having with tuning my first LMM.
OS: 8594 - 2007 truck with DPF, for now
Issue #1: Torque Reference PID does not work for LMM in V7.5 scan tool. It is not an available PID. This makes it impossible to monitor defuel or know if there is anything limiting your max torque that you are trying to command in the throttle pedal table which is carried to torque to fuel table which provides a fueling command. Did EFI Live ever enable the Torque Reference PID that works fine for LBZ on LMMs?
Issue #2: I cannot get it to command above 105 mm3 fueling. Have gone through all the tables available and the only one that may be limiting me is the torque table in the TCM. Anyhow, I can easily get around this issue by just modifying pulsewidth at 105mm3 and pretend like 120 mm3 isn't even there but for a DPF on tune I was just gonna leave the PW table alone and just allow 120 mm3 instead of the stock 95 mm3 to get a little extra power. Is maxxing out at 105 mm3 just something I should live with on the LMM as this is what everyone else is doing?
Issue #3: Zeroing the pilot quantity tables at certain areas (ie, full throttle) does NOT turn the pilot quantity off. Seems that there must be other tables governing the pilot quantity that EFI Live did not provide for the LMM. Zeroing cells in the pilot quantity table works fine for the LBZ. If forced to use the number of injections table under Fuel Pressure than you have to kill pilot for all loads at certain speeds and I don't want to do this. Just want to kill pilot at full throttle. Seems that the big time tuners would have complained to EFI Live about this one unless there is a workaround which is probably the case, I am just missing it.
Thanks in advance for any advice / direction.
garrettg.bpd
November 23rd, 2014, 10:47 AM
Bump
robof16
December 9th, 2014, 06:54 AM
The LMM spends a lot of time (sts) in the transient tables. The only way I’ve found to predict/control the timing is to copy the desired timing into the transient tables as well.
As a sanity check, look at your logs to see if it matches the transient table(s).
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