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Thread: LQ9 Swap and throttle is limiting with LS3 TB and x-link

  1. #1
    Tuner in Training
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    LQ9 Swap and throttle is limiting with LS3 TB and x-link

    We just got this running and the ECM seems to be limiting throttle to various percentages. Started with a 2006 LQ9, installed LS3 heads, intake, and throttle body with mini x-link, and Vinci cam. When trying to drive it shows the commanded throttle might be 21% restart without changing tune and got 50%. Only code that has set it MAF due to being disable to start VE table tune. Has anyone had any thing like this? Any help is appreciated.

    50% and 21% throttle.hpl

    2006 Silverado test 2-maf off-test 3.hpt

    throttle sweep.hpl

  2. #2
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    I changed PRNDL to none and same thing.

  3. #3
    What is this and whats it in? Have you verified what the throttle is doing?
    What are the TAC module and APP(pedal) from?
    Remove the air duct from the T/B and with the key on engine off have someone push on the gas pedal and verify that it is going wide open.
    Use the scanner to check throttle position.

  4. #4
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    everything is from the same 2006 Escalade, currently in a 70 Camaro. When the vehicle is off but key on it opens all the way. Here is a drive when it wouldn't open over 31.7%

    31.7 drive.hpl

  5. #5
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    connected Tech2 and swept it with the engine off and APP agrees and TB works fine but when driving it won't.

  6. #6
    What does the scanner read while driving?
    Does the scanner show anything different while driving?
    Snapshot it when the problem occurs.
    Did you reset the ETC Scaler to match the increased size of the T/B?
    It should be around .0208 for a 90mm T/B.
    Change that and recheck.
    It is in Engine-Idle-Airflow-General-ETC Area Scaler.

  7. #7
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    scalar is set to .0158 as directed by Torquerush, most things say .0192 tried that no change. Scanner shows will show commanded and actual match at 31% or 50% or 21%, what ever it sticks at that time. but the pedal will be floor and show 100% pedal. When it was commanding not more than 21% max speed was 40 mph and rpm was around 2000 and that's where it would stop, just like a rev limiter but it was slow to rev also.

  8. #8
    With the Tech 2 watch the commanded and actual TPS and APP while slowly opening the throttle.Engine off.Key on.
    If they don`t agree, or the % is greatly different it will cut power to the throttle blade motor,pull timing,cut cylinders.It also sets codes for the ETC.
    Does the throttle blade move smoothly? Key off,by hand.
    When this occurs, does the engine miss or run rich,won`t rev?
    Like it`s on fast idle, but runs rough?

  9. #9
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    APP will go to 100% but commanded Throttle will show 51.7% and actual is 51.7% (or what ever it limits it to that time) while driving. Blade moves free, it doesnt miss, it just won't rev beyond the 51.7%, when it was the 21% max rpm was 2200 and 40 mph, restarted then was 60 mph and 3500 rpm. Everything agrees it just won't let it open while driving and it changes on each restart of what the max % will be. Yes it is running a bit lean right now because I haven't wideband it yet due to it won't accelerate correctly yet.

  10. #10
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    Cleaned and grounds, swapped TAC, Swapped TB, and tried between each swap still the same. I have noticed when you first start it and it is at high idle it works fine but once it comes down to regular idle is is slow to respond and limits the opening amount.

  11. #11
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    Just found out they used a LS3 MAP sensor and the ecm is set for LS1 map, would that cause this??? I'm not around the car right now so I can't change the MAP tables but will let you know.

  12. #12
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    try maxing out the etc tps limit under torque management, if that doesn't work I would do a complete segment swap from from a 2006 escalade and transfer your changes over, says your running a pcm from a 2006 Silverado 5.3? the pedal and tb calibration could be different

  13. #13
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    TAC module, Pedal, TB, and OS are the same between the Silverado and the Escalade. On a compare file all settings are the same on the throttle between the 2.

  14. #14
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    Well for example when I converted to flex fuel I used the compare file and switched it all over to mine and the sensor still did not work, I had to do the segment swap and write entire for it to work. Maybe there's more stuff outside of the settings on hp.

  15. #15
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    OK, I'll check it out. Thanks!

  16. #16
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    Thanks, lsa_truck! I segment swapped and done the LS3 sensor and all works great.

  17. #17
    As a check, put the MAP back and retest. Iam very interested in the findings.
    thanks.

  18. #18
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    I'll try this weekend and let you know.

  19. #19
    As a check, put the MAP back and retest. Iam very interested in the findings.
    thanks.

  20. #20
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    Yup , uncorrect Map Value well cause this issue , but in most time we need a full segment & Write Entire once to make it all done