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Thread: Help with tune adjustments

  1. #21
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    I was just wondering what kind of tune this is? Is it supposed to be open loop speed density?
    1997 S10, 06 trailblazer SS LS2 swap, 4L70E trans, 76mm turbo. Factory ZQ8 suspension. 3.08, G80 w/a zexel. With a 0411 swap.

  2. #22
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    If it is open loop speed density, is the maf failed correctly? Making changes to the ve table wont have any effect if the maf is still working. The op says he was removing up to 30% fuel from the ve table and it has no effect. I think there is more than one table that needs to be changed to disable maf.
    1997 S10, 06 trailblazer SS LS2 swap, 4L70E trans, 76mm turbo. Factory ZQ8 suspension. 3.08, G80 w/a zexel. With a 0411 swap.

  3. #23
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    I mentioned the Wide Band O2 a couple posts back.

  4. #24
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    Quote Originally Posted by L31Sleeper View Post
    I mentioned the Wide Band O2 a couple posts back.
    So what ?? lol I didnt say anything about whether or not you told him to get a wideband. Im asking questions about what this tune is. ol cl sd maf? Im not making changes to his tune. Is the maf disabled in this tune?
    1997 S10, 06 trailblazer SS LS2 swap, 4L70E trans, 76mm turbo. Factory ZQ8 suspension. 3.08, G80 w/a zexel. With a 0411 swap.

  5. #25
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    WOW !! don't take ANYTHING I say personal

    The MAF is enabled and the VE IS still factored in the values are combined by the ECM.
    It is open loop right now, I didn't set it up that way.
    At first I thought he was on his way and needed some help, once I realized he didn't have
    a WBO2, I started thinking he should get all that stuff in place first.


    -Jusitn

  6. #26
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    My thinking was that this is a COS tune and the maf is supposed to be disabled in a 2 bar speed density tune? Also in a regular tune with the maf enabled closed loop, you can add as much fuel as you want to the ve table and it wont make any difference. But if you add fuel to the maf table it will make the afr richer.
    1997 S10, 06 trailblazer SS LS2 swap, 4L70E trans, 76mm turbo. Factory ZQ8 suspension. 3.08, G80 w/a zexel. With a 0411 swap.

  7. #27
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    Quote Originally Posted by slows10 View Post
    My thinking was that this is a COS tune and the maf is supposed to be disabled in a 2 bar speed density tune?
    It doesn't have to be Speed Density, It is currently a 2 bar Open Loop MAF tune.
    COS Allows you to remove the MAF without being stuck with the Low spark table,
    you are not required to disable or remove it.

    Quote Originally Posted by slows10 View Post
    Also in a regular tune with the maf enabled closed loop, you can add as much fuel as you want to the ve table and it wont make any difference. But if you add fuel to the maf table it will make the afr richer.
    Well any Closed Loop tune is going to try to stay Stoich that is how trims work.
    B0120 determines the RPM at which the ECM will use the MAF reading Exclusively if not disabled.
    So if you set B0120 to Zero the ECM will use the Only MAF data, if you set it to 12,000 RPM then
    the ECM will AVERAGE the VE and MAF data.

    -Justin

  8. #28
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    Peace Out
    -Justin

  9. #29
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    So engine idles, but stumbles when opening throttle...?

    Can it maintain steady speed at some load while driving...?

    Maybe try this:
    A-New-Twist-on-CALC.-VE-Table..Computing-the-Entire-VE-Table
    (summary notes says to set B0120 to disable VE while doing this).
    Last edited by joecar; May 29th, 2011 at 05:58 PM.

  10. #30
    Junior Member SuperChevy's Avatar
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    The engine runs steady under both cruise and acceleration. When the rpm get down to 1500 it stalls like the key is shut off. Once above 1500 I have not noticed any bobbles or rough spots.

    I am ordering a wide band O2 sensor and will get it in next weekend.

    Since I am new to this tuning and customizing does anyone know of a matrix or reference source (ie book to read) that would help me get a better understanding of how the tables interact with each other and how changes in the table affect the tune?

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