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Thread: 2014 Silverado 5.3 WOT lean shift from 1st to second and 3rd to 4th

  1. #1
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    2014 Silverado 5.3 WOT lean shift from 1st to second and 3rd to 4th

    ok guys the truck is a 2014 silverado completly stock with a K&N intake.

    When doing SD the VCM tables are populating to what seems to be correct. I did a couple of WOT street pulls and when it shifts from 1st to 2nd it leans out as well as 3rd to 4th the gauge reads fine when it is WOT going up to 5600 RPM or so when it shifts ( im 99.9% sure it is a false positive due to the truck being stock and not showing any signs of issues or cells) i am using an AEM 30-0300 kit for my wideband it is ran through serial port into the the laptop i am using the MPVI 2. i did the speed density histogram just like goat-rope garage on youtube had us doing it and it is in open loop with DFCO disabled. Don't know if it could be my gauge kit that came broken?? I just got it 2 days ago but it could be a defect.... i also did the free air calibration and it says pass so i'm assuming it's good. i did set PE to start at 4k with 50% throttle. I changed it back to stock but it did the same thing. I also loaded the AS found stock tune into it and it would still go lean on WOT shifts in the histogram. i don't have any filters on the histogram dont know if there is one for this? i did try at one point the accelerator pedal filter to filter out unwanted 0% pedal hits and that works for the 0% (like its supposed to). i have a replacement guage on order with amazon and i will try that new one out to see if it works out tomorrow until then i would greatly appreciate any other pointer i can get from you guys. i have attached a log file and my tune ( not much cause its pretty much stock lol )
    Attached Files Attached Files
    Last edited by cruz1383; 02-29-2020 at 08:36 PM.

  2. #2
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    Cant check the file from here. Trans can request fuel cut to lower engine torque during shifts, that may be the case?

  3. #3
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    Grandam75 is exactly right. Look at the injector PW during the shifts. It's fuel cut. The timing is also dropping down to -10 degrees or lower.

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    Thank you Grandam75 and Kevin. now that we might have the culprit what are my remedies for it. What tabs would i need to start with? anymore guidance would be greatly i have looked at the spark retard section and dont see anything that stands out to me.

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    I know for the 8L90 we don't have access to everything we need, so mine cuts fuel as well on shift along with timing. We can only enable/disable the torque reduction for certain situations (power downshift, TUTD, closed throttle, etc.) There is options for "Limit Torque Management" which is supposedly for "tip in" but it dosent seem to do anything that I can notice.

    I am assuming you have a 6L80 though, so you may have the options in the TCM tune.

    Whats weird is I see mine completely cut fuel on one bank but the other is still fueling, which I would think you would get some really bad engine operation if this was the case.

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    ok? so is there a filter that people are using in order to weed out the false data in the scanner? thanks for your help cMitchell17 by the way.

    ok i have a torque reduction tab under transmission/torque management/general

    it says upshift enabled should i change any of these settings? dont want to go WOT and have my tranny kicked out on the side of the road lol

    Screenshot (1).png
    Last edited by cruz1383; 03-01-2020 at 02:48 PM.

  7. #7
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    anyone have any other thoughts on this??? i changed the torque reduction up-shift settings and it didnt do anything. problem is still happening.

  8. #8
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    Set pressure pattern mode to "special" and it prevents fuel cut on some OS.

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    thank you for the advice....will that be all the pressure patterns X,Y,Z modes ?
    Last edited by cruz1383; 03-02-2020 at 03:36 PM.

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    Quote Originally Posted by cruz1383 View Post
    thank you for the advice....will that be all the pressure patterns X,Y,Z modes ?
    You can do it for all, but your tune currently only uses Pattern X for all modes.

  11. #11
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    Oh ok thank you for this going to do it and report back with the findings

  12. #12
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    ok just got back and Sevinn you are the man..... worked like a charm. thank you so much i was pulling my hair Bud for a while on this.

    Screenshot (4).png
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    Last edited by cruz1383; 03-02-2020 at 04:06 PM.

  13. #13
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    Happy to help. This simple filter usually will filter out fuel cut on shifts. Just looks for commanded EQ being less than 1 and the slope of RPM being positive for the last 250ms.

    [50070.56.slope(250)] > 0 and [50118.238] < 1

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    thanks again Sevinn i will use this also when i tune. i have made some good progress now on my truck really loving it. i had been chasing my tail for about 2+ months; first with the ballenger afr500v2 not being able to do serial and then with the AEM 30-0310 X-Series Inline Wideband just not reading right (all over the place) to this whole fuel cut thing lol it's a miracle i stuck it out or hardheadedness...

    just a quick question ...for this filter you just write it as you did with the (and) in between?
    Last edited by cruz1383; 03-03-2020 at 06:45 PM.

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    Quote Originally Posted by cruz1383 View Post
    thanks again Sevinn i will use this also when i tune. i have made some good progress now on my truck really loving it. i had been chasing my tail for about 2+ months; first with the ballenger afr500v2 not being able to do serial and then with the AEM 30-0310 X-Series Inline Wideband just not reading right (all over the place) to this whole fuel cut thing lol it's a miracle i stuck it out or hardheadedness...

    just a quick question ...for this filter you just write it as you did with the (and) in between?
    You'll be happy you did stick it out. Glad you're making it now!

    And yeah, paste it exactly as I put it. As long as you're logging RPM and commanded EQ it will work. There is much more robust filtering you can do but this basic one really cleans up alot for wot stuff.

  16. #16
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    What problems are you having with the AEM? I got the 30-334 X Series and maybe I am having the same problem because I am going in circles trying to tune VVE because I feel like my wideband is picking up transients and I've tried derivative filters to try and only capture steady state but I can't get anything to work. On top of that everytime I try to calculate there coefficients it throws other cells off too even when I try to isolate zone boundaries.

  17. #17
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    Quote Originally Posted by cmitchell17 View Post
    What problems are you having with the AEM? I got the 30-334 X Series and maybe I am having the same problem because I am going in circles trying to tune VVE because I feel like my wideband is picking up transients and I've tried derivative filters to try and only capture steady state but I can't get anything to work. On top of that everytime I try to calculate there coefficients it throws other cells off too even when I try to isolate zone boundaries.
    What kind of filters are you using? Care to share a log that you feel you are having erroneous data in? I'd be happy to take a look.

  18. #18
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    well i was getting weird number with the 30-0310 X-series ( the one with no gauge) in the morning it would read one thing then in the afternoon it would read another thing. i though ok maybe it is cause the air is more dense outside in the morning. i would then try to tune on an afternoon and do 3-4 different tunes of just driving around with some WOT but all the data was completely off with lean in one on a cell in the first run then 13% rich on another run and i was like, how the hell does anyone tune like this. i was using past half percent on the VVE tables by the way. That's what led me to be suspicious of the tune i was doing as well as thinking something might be wrong with the wideband. i then saw videos on youtube (goatrope garage and others) and the number were not going all over the place on there computer so i was like WTF..... I then said well i got the money and i'm not going anywhere at this rate might as well try a different wideband and see what it does. now here i am and the tuning seems to be going good, i'm getting closer and closer with numbers. They just dont just go crazy they stay consistent and lowering or raising where they should, when i do the paste and calculate coefficients.

    Sevinn i would love to learn more of these robust filters as i go along. I have also heard of guys doing big number with just MAF tuning also... i come on here and read all kinds of threads and other peoples problems and see what solutions people come in with to see if they work and when they do i write them down in a none pad.
    Last edited by cruz1383; 03-04-2020 at 03:05 PM.

  19. #19
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    Here is one log where I have some higher rpm data. I also often find I will let it idle a little before I stop logging and I will think I will be lean then I let it idle and within a few min the cells will turn rich, it just dosent make any sense unless there is something in the tune where I don't completely have open loop running and there is some kind of feedback. I have also zeroed out all the prediction coefficients since some people have said that messes with things. I've been searching also to see if anyone has come up with better filters but everyone just seems to use the count as the only filter. I have tried mostly RPM and TPS derivative filters which just cut out data where the derivative is high but they don't seem to be acting like you would think and they don't really give you better data as after they are filtered you can still see cell boundaries that are really discontinuous.

    So the forum won't let me attach the log, here is a one drive link:

    https://1drv.ms/u/s!AkCUE89IhD0Ng-A2...Uh5jg?e=CV0Rto

    Thanks for the help, I have done what seems like millions of iterations of logging and correcting and reflashing and it seems like rather than converging towards less error, the error is growing.
    Last edited by cmitchell17; 03-06-2020 at 03:55 PM.

  20. #20
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    cmitchell17 you can try this

    [15026.156] >1 you do need to be logging accelerator pedal position in order for it to work.

    i also tweaked (all i did was put a 2 at the end instead of the 1) Sevinn's filter he posted and it weeded out a lot of the false data you had on your graph. you had a 23.26 error ratio on there and with this filter it weeded that out which was more then likely a false positive from holding the throttle too lightly or letting off throttle and HP tuners still picking it up.

    [50070.56.slope(250)] > 0 and [50118.238] < 2
    Last edited by cruz1383; 03-10-2020 at 10:10 PM.