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Thread: lc1 BEN factor for auto ve leaning out afr

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  1. #1
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    Default lc1 BEN factor for auto ve leaning out afr

    Hi, I have a 408 running an ls1a pcm and i'm trying to run the auto ve tutorial. I followed it step by step and when I copied and pasted the BEN chart into my backup VE table it was a .8 multiplier across the board and it leaned the motor out even more then it already was. I attempted a second log of data to get even closer but was so lean the car just fell on its face after leaving the driveway I had to load an older tune back in. I was expecting to have some 1.x numbers on the chart since at certain rpms I was running a little lean. I'm still a beginner at tuning but I have done a lot of searching and can't find an answer. Something that seems funny is the tutorial wants the commanded AFR logged and it shows 8.62, I'm running e85 so I have my stoich input set to 9.7 i believe but I don't know why it wants such a rich commanded AFR.

    I attempted to attach my auto ve log, hopefully it shows my BEN factor and anything else you may need.

    thanks for any help/suggestions
    Attached Files Attached Files

  2. #2
    Joe (Moderator) joecar's Avatar
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    Set Stoich back to stock (14.63 for F-car or 14.68 for Y-car) in the tune, and redo AutoVE


    ( the LC-1 reports AFR based on stoich 14.7, so the PCM's commanded AFR must be based on the same Stoich (14.63 and 14.68 are suffciently close).

  3. #3
    Joe (Moderator) joecar's Avatar
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    It also looks like your widebands are not working.

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    Joe (Moderator) joecar's Avatar
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    Default ...or do this...

    Set B3601 Stoich AFR to 9.7 in your tune...

    and then do either one of these:
    a. create calc pids for LC-1 AFR based on stoich 9.7 and BEN based on this AFR (e.g. BEN is {CALC.AFR_LC11}/14.7 * 9.7/{GM.AFR}).
    b. create calc pids for LC-1 lambda and BEN based on this (e.g. BEN is {CALC.AFR_LC11}/14.7 * {GM.EQIVRATIO})


    I prefer b.


    ( of course you combine the math 9.7/14.7 = 0.65986 )
    Last edited by joecar; September 29th, 2017 at 08:20 AM.

  5. #5
    Joe (Moderator) joecar's Avatar
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    If you use Lambda and/or EQR instead of AFR, there will be less confusion

    ( and NA PE should be set to about 0.85-0.86 regardless of stoich AFR )

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    okay so I had my 3601 table set to 9.71 while i was attempting to run the auto ve, if I switch it over to 14.7 while running e85 won't the computer lean the motor way out? I typically log everything in lambda and cross reference it to an e85 chart to keep things more simple. why do you think my wideband isn't working? right now i'm running with no 02 sensors just an open loop tune with MAF support. I'm trying to dial in my VE table so I can run with no MAF and have more control over fueling. The way its setup now when I make a change to the VE table the AFR never changes, the MAF must be doing all the talking.

  7. #7
    Joe (Moderator) joecar's Avatar
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    Quote Originally Posted by 98camaro408 View Post
    okay so I had my 3601 table set to 9.71 while i was attempting to run the auto ve, if I switch it over to 14.7 while running e85 won't the computer lean the motor way out?
    Yes, that's what will happen... I was trying to point out that working with AFR make it harder and confusing... so I then wrote the next post about calc pids.

    I typically log everything in lambda and cross reference it to an e85 chart to keep things more simple. why do you think my wideband isn't working?
    Its reading mostly 7.8...

    right now i'm running with no 02 sensors just an open loop tune with MAF support. I'm trying to dial in my VE table so I can run with no MAF and have more control over fueling. The way its setup now when I make a change to the VE table the AFR never changes, the MAF must be doing all the talking.
    Are you seeing a MAF DTC...?

    If you don't see a MAF DTC:
    the PCM will continue using the MAF, and if the MAF is not physically present, the PCM calculates what it should/might have read.

  8. #8
    Joe (Moderator) joecar's Avatar
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    I typically log everything in lambda and cross reference it to an e85 chart to keep things more simple. why do you think my wideband isn't working?
    Quote Originally Posted by joecar
    Its reading mostly 7.8...
    I meant AFR 7.38 for LC12 and AFR 7.45 for LC12...


    you logs show that both wideband flatline at AFR 7.38...

    this means that your LC-1's are putting out zero volts... they're not working or not connected properly... ( do you have wideband ground connected to FS...?)

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    so I just looked on the efilive help tutorial on how to create calcpids and I don't fully understand how to do it. I think I will try setting my 3601 back to 14.7 and see what happens, I have my lc1 display set to show afr based on e85 stoich so if it gets crazy I'll just shut it down, plus I log in lambda anyways so I should see it on there as well.

  10. #10
    Joe (Moderator) joecar's Avatar
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    Quote Originally Posted by 98camaro408 View Post
    so I just looked on the efilive help tutorial on how to create calcpids and I don't fully understand how to do it. I think I will try setting my 3601 back to 14.7 and see what happens, I have my lc1 display set to show afr based on e85 stoich so if it gets crazy I'll just shut it down, plus I log in lambda anyways so I should see it on there as well.
    Do this: set B3601 to 9.7 ( there are kits to measure alcohol % content in gasoline, then you can cross-reference it to the stoich AFR to use).

    Then let's take a look at your calc_pids.txt file, post it here, it's located under c:\user\<you>\Documents\EFILive\V7.5\User Configuration.

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