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Thread: Twin Turbo 5.3 running lean

  1. #1
    Junior Member
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    Dec 2014
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    33

    Default Twin Turbo 5.3 running lean

    I hate to ask but I'm stuck and can't seem to figure out what I'm doing wrong. I have a bone stock gen 3 5.3 with twin turbos, decapped injectors, 3 bar map, and 4L80E. I have received a tune from another person and I have been trying to make changes to this custom operating system without any luck. The original tune works fine except for the fact that it runs dangerously lean. Any time that I try to make a change to this tune it won't run past idle. AFR is 10:1 at idle and then changes to absolute lean and doesn't sound like it's firing off of idle. As soon as I let off the gas it idles again just fine. I've tried changing injector flow rates, Main VE and Boost VE. I've tried the online tutorial also step by step and the car does the exact same thing so I have not been able to do much data logging. Anyway, attached is the only tune I can get to work and the only good data log I've been able to save. If anyone has any suggestions, I'd greatly appreciate it.
    Attached Files Attached Files

  2. #2
    Lifetime Member wesam's Avatar
    Join Date
    May 2010
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    660

    Default

    What injectors do you have ?
    for the fuel system is it vacuum referenced ?
    you have a lot of problems with your tune but I need this information to fix it for you
    EFILive Tuner

  3. #3
    Joe (Moderator) joecar's Avatar
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    Apr 2003
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    28,403

    Default

    also:

    did you measure rail pressure (with reference hose removed)...?



    B3618: set the low cells to same value as higher cells (i.e. all across).

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