Page 1 of 7 12345 ... LastLast
Results 1 to 20 of 129

Thread: LNF- Torque Management Inj Disable kills DFCO- WTF?

  1. #1
    Advanced Tuner
    Join Date
    Jan 2009
    Posts
    792

    LNF- Torque Management Inj Disable kills DFCO- WTF?

    Ok I've had torque management injector disable zeroed out for quite awhile now, and in trying to find the cause of a decel backfire and excessive "burbling" I found out it might not do exactly what it says it does. The description says- "Torque Mgt Cylinder Disable: Defines which cylinders will be disabled for tqmgt. Set to 0 to disable cylinder cut."
    I found that putting this table back to stock took away the decel backfiring and burbling, and I again have dfco shown in the logs by the WB going full lean. The fuel cut status bit still shows it's turning on, but with the table zeroed out it obviously isn't cutting fuel. I looked back at my logs and found I haven't had any dfco for quite awhile. I went back and forth between stock and zeroed out cylinder cut table (no other changes) and every time the logs showed WB either going full lean (stock table) or not (zeroed table) on decel.

    So, my question is, what does torque management have to do with dfco??? Any of you LNF guys that have the injector cut table zeroed out might want to check their logs and try putting the table back to stock and see what happens. Decel is a lot nicer with dfco working (at least for me on my car), and it could only help mileage too.

  2. #2
    1 ? I have.
    Does everyone zero out the table or do some have the lower right hand cell with 15?
    I have a custome tune by a tuner in Canada and instead of all the cells zeroed he has the last one at 15.
    Other than a tune and a k&N filter my car 07 Solstice GXP is stock and I can tell you I get the decel burble and my A/F on at least the DashHawk from the PID shows a strange # of something like 29AFR. Haven't seen what it says on HP tuners though.
    I also have a Supercharged Ford Truck that has a LM1 installed and on decel I get the burble but my AFR reads on the LM1 reads 20.9 which is straight atmosheric air going through the system.
    Why the difference?

  3. #3
    Zeroing out the table will kill dfco, yes. I kinda like the gurgle w/a catless and a open dump. <shrug>

  4. #4
    Senior Tuner Iam Broke's Avatar
    Join Date
    Jul 2009
    Posts
    2,305
    I have mine set to all zero's ('08 TC) and I still have DFCO, always have above 2k in 4th & 5th anyway. Been that way since last summer.

    FWIW, the table link in HPT calls it Inj Disable, but the table itself is labeled cyl disable in mine.
    Last edited by Iam Broke; 04-03-2010 at 09:02 AM.
    '12 Camaro T3 2SS/RS LS3 M6, SLP TVS 2300, Flex Fuel

  5. #5
    Advanced Tuner
    Join Date
    Jan 2009
    Posts
    792
    Oh great, my decel is nice now but my misfiring on high rpm or NLS shifts is back! I haven't tried zeroing back out the cylinder cut table but I'm betting my misfiring will go away again if I do.

    So now the trick is to stop misfiring on shifts AND have dfco for a nice decel. Maybe that's why Tazz's tuner left the 15 in that one cell? Hey Tazz can you try logging in HPT and see if you're getting dfco still? It's pretty obvious in the logs because the WB reading will flatline at 1.99 on decel.

    Anyone else have any ideas?

  6. #6
    Quote Originally Posted by gmtech16450yz View Post
    Oh great, my decel is nice now but my misfiring on high rpm or NLS shifts is back! I haven't tried zeroing back out the cylinder cut table but I'm betting my misfiring will go away again if I do.

    So now the trick is to stop misfiring on shifts AND have dfco for a nice decel. Maybe that's why Tazz's tuner left the 15 in that one cell? Hey Tazz can you try logging in HPT and see if you're getting dfco still? It's pretty obvious in the logs because the WB reading will flatline at 1.99 on decel.

    Anyone else have any ideas?
    Spark plugs, get ngk 3787's, problems solved.

  7. #7
    Advanced Tuner
    Join Date
    Jan 2009
    Posts
    792
    Spark plugs, get ngk 3787's, problems solved
    Already running them. Bummer. The only thing the NGK's did for me is give me a crappy cold start.

  8. #8
    Advanced Tuner
    Join Date
    Jan 2009
    Posts
    792
    Ok, I'm getting closer to figuring this table out...
    I zeroed the whole table except for the lower right cell, I left 15 in that one. Just a quick log this morning but it did show a difference. Dfco is killed on decel, but still works on shifts. This is actually the opposite of what I want, but at least I learned something from it. Fuel cut status pid shows it's going into dfco on decel, but the WB isn't going anywhere near full lean. It does cut fuel and go full lean on shifts. My next step is trying everything zero except for the 3rd row down, leaving 15 in the right end cell.

    This thread gave me some ideas, but it looks like nobody really figured it out for sure?...

    http://www.hptuners.com/forum/showthread.php?t=20339

  9. #9
    Advanced Tuner
    Join Date
    Jan 2009
    Posts
    792
    Ok, did a little more "testing" last night, tried the table 6 or 8 different ways. Guess which way ran the best? The ENTIRE table set to 15's! Now that sure goes against what most people (me included) were thinking about this table.

    Here's what I've figured out so far about this Torque Mgt Cylinder Disable table... (still need more logging to verify some of my ideas.)
    The table definitely does more than just torque management, it also controls dfco. The columns seem to me to be some sort of severity or sensitivity amount. I think Chris was saying no but putting 15's in the first column makes it more likely to go into full lean dfco or cyl cut. If you have low numbers in there it goes into fuel shutoff, but doesn't go full lean. (Appears to be only cutting 1,2 or 3 cylinders instead of all 4?)

    I tried to figure out the rows, but putting a 15 in the last column of each row one at a time gave inconclusive results. Still have no clue about the rows.

    Having the table stock or with all 15's will still make the NLS or high rpm misfires happen, when you have it all 15's it's very severe. I believe the way around this is making sure all the other tables that control torque are set high enough so it won't try to limit and use this table for torque control in the first place. I put my "Max Torque" table to all 100's and raised my rev limiter to 7k to make sure I don't trigger that. Any other torque limit tables I set to 100, at least at high rpm's. So far no high rpm or NLS misfiring! (fingers crossed) It would be awesome if part of this table was for dfco and part was for torque mgt so we could zero out the torque rows or columns and keep the dfco rows or columns working.

    Here's the big one...
    THESE MOTORS RUN WAY BETTER WITH DFCO. Sorry I yelled but OMG even my son noticed how much smoother it ran with dfco working, actually when I had the entire table filled with 15's. And he wasn't even driving! Without dfco there's just too much burbling and backfiring (my opinion of course), not only on decel but during shifting also. With it cutting fuel during shifts it goes through the gears SO much nicer, just sounds and seems cleaner. Mileage can't help but be better, maybe way better. Decel is a constant note, which it actually should be anyway. I wasn't thrilled with the way my car had been running since a zeroed out the cyl cut table a month or so ago, and I spent a ton of time trying to get the decel backfiring tuned out with no success. (A good example is do a full throttle first gear to the redline, then cut the throttle and push in the clutch. On mine with the table zeroed it would backfire terribly all the way down to idle. (pop pop pop pop pop...) With the whole table at 15's you can do the same thing and it just drops rpm smoothly like it should.) I finally realized it was the lack of dfco that was causing the drivability problems. BTW, even having the table all 15's has no effect on power, it only will if you trigger some torque reduction mode. This is all about drivability.

    Time will tell what ill effects having this table back to stock or with all 15's will bring up, I'll keep mine that way for awhile and see how it goes. Does any of this make sense compared to what you guys have seen? Chris? I don't believe you can kill the motor trying it so if your tables are zeroed you might want to try back to stock or all 15's. Probably doesn't have to be all 15's but until we know what the columns and rows actually stand for we're just guessing.

    I did notice one more important factor, when the status pid shows fuel cut off and the WB shows it is going full lean (1.99) it locks the fuel trims (like it should). If it shows fuel cut off in the status but ISN'T going full lean, or just partially leaning it out (maybe using the first lower severity columns of the cyl disable table???), it will NOT lock fuel trims, which will make tuning difficult at best. This to me is a big factor, at the very least knowing that it's locking or not locking fuel trims during dfco. That's why I tried the whole table 15's, if it wants to cut fuel for dfco, I want it to cut ALL cylinders and lock fuel trims.
    Last edited by gmtech16450yz; 04-06-2010 at 05:15 PM.

  10. #10
    Advanced Tuner
    Join Date
    Jul 2009
    Location
    Winfield/Ofallon MO
    Posts
    600
    OK, I've been watching this on my RPD, I don't get DFCO with all 0s but the previous problem with the RPD and not HPT since I've been doing driving with wife and kids in the car. When trying to into DFCO for a couple seconds, the RPD afr blanks out. This might be the underlying problem with the RPD blanking is that its not actually going into DFCO and its throwing a code(that doesnt pop up a cel) IDK if you have the RPD but I know everyone with the RPD has experianced this problem maybe because DFCO isn't working....

  11. #11
    Advanced Tuner
    Join Date
    Dec 2008
    Location
    Reading, PA
    Posts
    352
    gmtech16450yz, thank you for posting this valuable info and your thoughts on it.

    Stuff like this is why I didn't modify this table given the very vague description and lack of instructions that we got with it. Hell, now I may go back and raise the values to 15's.

    Thanks again!
    2013 Cruze Eco - CAI, Catless DP, Catless MP, ZZP FMIC, Ported Intake Manifold, Mild tune (17psi), best 43.5mpg, 175ftlbs (pid)

    2008 Solstice GXP - ZFR 6758, catless, AEM stage 1 water/methanol injection, Hahn Racecraft Intercooler, solo street race cat back, LE5 throttle body - 307whp on a dyno dynamics (stock turbo numbers), 100 octane EFR6758 numbers - 463whp/454wtq

  12. #12
    Advanced Tuner
    Join Date
    Jan 2009
    Posts
    792
    gmtech16450yz, thank you for posting this valuable info and your thoughts on it.
    You're more than welcome! I was beginning to wonder if anyone cared. To me this was a big drivability factor. I knew something in my tune was making the decel and shifting kinda crappy since the stock tune had a nice smooth decel and shifts. Just took me awhile to figure it out because I didn't realize a torque management table would have anything to do with dfco. I guess that's what makes this all kinda fun (and a little frustrating), trying to figure out what GM is doing in these computers! The huge difference you can get between stock and properly tuned sure makes it worth the trouble though.

    Ok, I tried 15's in the far right column and the rest of the table zeroed, I saw no difference between that, all 15's, and stock as far as dfco is concerned. Seems to make sense since dfco should be all cylinders or nothing. (meaning it should only be the cells with 15's in them, which supposedly means all 4 cylinders??) I didn't get a chance to try any nls or high rpm shifts, but maybe that's how we'll retain working dfco AND eliminate any torque reduction cylinder cut.

    Like I think I said before, I'm just guessing and coming up with theories on this table, tuning and logging to see if what I'm guessing is what's actually happening. If anyone wants to experiment, try keeping the stock 15's in the far right column and zeroing out the rest of the table. Lemme know what you think and what your logs show and maybe we'll get a handle on this table and move on to something else!

    Thanks.

  13. #13
    I've tested this today, and you're right. The car does feel much better, it also does not pop and crackle on decel. I'm interested to see how this effects my gas mileage since mine has been particularly shitty lately.

  14. #14
    Senior Tuner Iam Broke's Avatar
    Join Date
    Jul 2009
    Posts
    2,305
    I've had this table at all zero's since last fall, been getting intermittant P2237 02 pumping ckt codes with no CEL, but locked STFT's intermittently after long DFCO's for no good reason. I set this table back to stock tonight to see if it helps that. Hopefully everything else is high enough at 100% and 7200 rpm that it won't fall on it's face at WOT. Time will tell, thanks for all the input gmtech!
    '12 Camaro T3 2SS/RS LS3 M6, SLP TVS 2300, Flex Fuel

  15. #15
    Advanced Tuner
    Join Date
    Mar 2009
    Posts
    676
    Interesting. I have been having some serious throttle hang issues that are just annoying, like the engine is not decelerating properly. I wonder if this has anything to do with it or not?

  16. #16
    Advanced Tuner
    Join Date
    Jul 2009
    Location
    Winfield/Ofallon MO
    Posts
    600
    My throttle does the hanging as well, guessing this is all connected. Not sure if I want to go back to stock or 15s just yet, figure I'll wait on you guys to figure it out lmao. I have some 3787 plugs on the way and I need to figure out what air filter I'm gonna go with since its a sorta cone type filter, not a panel filter.

  17. #17
    Advanced Tuner
    Join Date
    Jan 2009
    Posts
    792
    So far, I think 15's in the far right column (all rows) and the rest zeroed out seems to be the ticket. Dfco seems to be all 4 cylinders or nothing, which would mean the 15's. Torque management seems to be just a couple cylinders when it's not an extreme situation, so zeroing everything but the 15's should keep minor torque reductions from cutting cylinders. If it's major it should still cut all cylinders but maybe we don't get into major torque reduction very often even with a crazy tune???

    On the throttle hanging... Make sure your DAL's aren't too high in the cells it would be in on decel. Look at your logs, decel load doesn't go straight to zero (actually never goes to zero, mostly around 8-15) it makes it's way through the higher load cells on it's way down to idle or decel. If you have your DAL's higher in other than the 100 column, it might be making your decel hang. Make sure DAL's are stock or maybe even lower in the high rpm 10 to 70 or even 90 load columns. Try going extreme, like cutting them in half and see what happens. If you stay above the 1500 or 2k rpm rows you shouldn't have any stalling problems from going too low.

    Thanks guys, glad to help.

  18. #18
    Senior Tuner Iam Broke's Avatar
    Join Date
    Jul 2009
    Posts
    2,305
    Didn't get to drive it with the stock settings today, other stuff going on. Hopefully tomorrow to see how it goes.

    Had to take the T/A in for emissions... stock tune in, drive 50 miles, test, pass, drive home , take stock tune out.


    Edit...decided to try all 15's in the right hand column, zero's everywhere else. Made a 10 mile run, 27 psi spike to test it, didn't fall on it's face. DFCO seemed the same on mine as all zero's though. I'l see next week if it still gets a P2237 at all. Made a very long DFCO tonight and it didn't pop a pending code yet.
    Last edited by Iam Broke; 04-09-2010 at 06:49 PM.
    '12 Camaro T3 2SS/RS LS3 M6, SLP TVS 2300, Flex Fuel

  19. #19
    Senior Tuner BackyardTurbo_FTW's Avatar
    Join Date
    Jul 2009
    Location
    East Suckburg, PA
    Posts
    1,163
    I returned the table to the stock settings and Im liking it better lately. I haven't had a 2237 code since

  20. #20
    Senior Tuner Iam Broke's Avatar
    Join Date
    Jul 2009
    Posts
    2,305
    Drove it 3 long trips now with the right columns all 15's no more P 2237 either. 25 sec DFCO coming down from 110 the other day. Looks like that being all zero's may have been the culprit. Still able to boost 27 psi in the midrange without anything falling on it's face. Next tune update (maybe Fri) I'll put it back to stock for a week.
    '12 Camaro T3 2SS/RS LS3 M6, SLP TVS 2300, Flex Fuel