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Thread: E38 Missing tables? Or I'm missing something?

  1. #1
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    Default E38 Missing tables? Or I'm missing something?

    Hi Guys, or Ross, I've run across some E38 weirdness (one of many) that I can't figure out without help, I'm hoping somebody can figure it out!

    I've been trying to smooth out the AFM transition from 4 to 8 cylinders and I've been getting torque reduction retard that I can't change with any of the available tables in EFILive. I've gained so much torque and throttle response tuning the V8 side, the transition from 4 to 8 causes quite a noticable surge in power. (You can see the sharp jump in torque in the log jpeg.) If I can change the timing retard (hopefully soften the sharp retard decay) I can make the transition much smoother. Nothing I've tried has any effect on this retard (shown in jpeg), except for the overall min timing table that effects everything, and that only sets how low the retard can go.

    Hey Ross, can you please take a look at this OS and see if there's some tables missing you could possibly add in to the next release? Retard shows up in logs as SEMRET, timing retard due to torque reduction, but no torque reduction or torque management tables change this particular retard.

    Vehicle is an '08 GMC Sierra V-Max 6.0
    OS #12617631
    I'm using the latest version of EFILive. (7.5x, not bbl 8.0) I don't think this is just something I'm missing or don't know how to do, it's certainly possible though. I know you're really busy, that's why I've waited to bug you until I REALLY needed help!

    Thanks!
    gmtech16450yz (lurked and gotten plenty of info from the forum for a long time, just signed up now to ask this question.)


  2. #2
    Senior Member alian's Avatar
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    Hey Mate.I crindged when I saw that pid. about 6 months ago I asked a similar question. Same pid pulling up to 15deg at wot. After playing withevery thing I could find. we ended up finding that it was the auto reduction. when we 0ed that out in the up and down shift and that removed the problem. Hope that helps
    Cheers Ian

  3. #3
    Joe (Moderator) joecar's Avatar
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    gmtech16450yz, welcome

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    Thanks for the replies guys.

    I wish it was just simply TM spark retard Alian, that would make it easier to deal with. Zeroing out all TM in ECM and TCM have no effect on this retard. It has to be a parameter that is in the OS that isn't in EFILive. Hopefully that is, unless it's not even in the OS. If I had control over the TAC parameters that would also give me the tools to fix what I'm working on. GM raises TAC momentarily when going INTO 4 cyl mode, what I need to do is lower TAC (or retard timing) when going out of 4 cyl mode to soften the torque increase. The switch from 4cyl to 8 on my truck is as much as 80 ft. lbs. of torque increase, that's noticeable and kind of annoying.
    Sure would like to fix it. (wink wink...Ross are you out there?)

  5. #5
    Forum tyhee Site Admin GMPX's Avatar
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    Yeah, I'm out here, but as per usual distracted coming up with a work around to changes GM make with this on going issue..........
    http://forum.efilive.com/showthread.php?t=9528

    Cheers,
    Ross
    Need official EFILive help, please go here.
    For tuning support please post your questions on this forum (or other auto forums).
    Sorry if I don't respond to your PM, don't take it personal.


  6. #6
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    Thanks Ross, sorry to bug you, I can imagine how busy you are. I've been dealing with GM's "new, improved" models for almost 30 years now and I know how much fun it can be.

    I just had a GMC Acadia with an XM station scanning problem in the nav radio that I ended up fixing by replacing the Onstar module. Seems the Onstar VCIM couldn't talk nice to the nav radio on the network and made it do things it wasn't supposed to do! Not being able to really "see" what's going on makes things like that a lot harder than they need to be.

    Is this missing parameter something I can make a .cax file for? I have no experience with that but I can read up on how to do it and figure it out. I sure would like to fix my AFM problem, and there's a few other things I'd like to tweak too if there were tables to do it. (Like a multiplier to timing based on mph or trans gear, that would be nice.)

    Thanks again, and if you do happen to get some spare time to put together the table(s) I need I'd be forever indebted to you!

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