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Thread: Cold Start Help....240sx swap transvestite!!!!

  1. #1
    Senior Member exploder's Avatar
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    Default Cold Start Help....240sx swap transvestite!!!!

    I recently completed a ls swap into a buddy of mines 240sx. The car runs great on hot start and everywhere else. The car is equipped with the cable throttle I cannot for the life of me seem to keep this car running without my foot on the gas until it finally catches an idle and then it is fine. The engine details are as follows.

    346ci
    11.5:1 diamond domed pistons
    MS3 cam
    LS6 intake
    cable TB
    long tube headers no cats
    PLX wideband

    I need help getting this sorted. I have added a ton of airflow, added timing, added to the startup friction tables. I am at a loss. Let me know what PID's to log and I will do that as well. Here is a copy of the tune file.
    Attached Files Attached Files
    03 z06 auto
    ver7.5.5 custom OS5
    415 ci
    239/255 .624 lift LSr grind
    16psi
    Meth injection
    PLX WB02

  2. #2
    Lifetime Member
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    Dec 2007
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    1,143

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    Quote Originally Posted by exploder View Post
    I recently completed a ls swap into a buddy of mines 240sx. The car runs great on hot start and everywhere else. The car is equipped with the cable throttle I cannot for the life of me seem to keep this car running without my foot on the gas until it finally catches an idle and then it is fine. The engine details are as follows.

    346ci
    11.5:1 diamond domed pistons
    MS3 cam
    LS6 intake
    cable TB
    long tube headers no cats
    PLX wideband

    I need help getting this sorted. I have added a ton of airflow, added timing, added to the startup friction tables. I am at a loss. Let me know what PID's to log and I will do that as well. Here is a copy of the tune file.
    Are you adding cranking fuel as well? Additional air will need fuel as well.

  3. #3
    Senior Member exploder's Avatar
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    It already runs slightly rich on startup and leans out as the car warms up. Starting around 12.5AFR and leans to 14.5-7 at operating temp.
    03 z06 auto
    ver7.5.5 custom OS5
    415 ci
    239/255 .624 lift LSr grind
    16psi
    Meth injection
    PLX WB02

  4. #4
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    Dec 2007
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    Quote Originally Posted by exploder View Post
    It already runs slightly rich on startup and leans out as the car warms up. Starting around 12.5AFR and leans to 14.5-7 at operating temp.
    It may run rich once it fires and switches to the open loop table from the cranking table but may not have enough cranking fuel. Depends what "startup" means.......cranking or after it has fired.

  5. #5
    Joe (Moderator) joecar's Avatar
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    Hi Exploder,

    gmh308 is saying to also look in Engine Calibration->Fuel->Crank/Start.

    LOL... a 240SX cross-dresser... I had never heard it referred to like that...

  6. #6
    Lifetime Member mr.prick's Avatar
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    You can adjust cold start AFR with {B3605} if it is too rich or lean.
    If the table is displayed in EQ use WBO2 Lambda as a multiplier,
    if it is displayed in AFR or Lambda use EQ as a multiplier.
    This way stoich is always the target.
    512k RoadRunner Firmware 12.14R
    FlashScan V2 Bootblock V2.07.04 Firmware V2.07.22 EFILive V7.5.7 (Build 191) V8.2.1 (Build 181)
    LC-1 WBO2

    _________________________________________________

  7. #7
    Senior Member exploder's Avatar
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    I adjusted several things you guys mentioned. Unfortunately none of them helped too much. It will initially fire and the rpms will go up to about 1300rpm and then just fall right back down and stall out. If I give it a little gas and hold it until it goes into closed loop it is fine. Any other ideas?
    03 z06 auto
    ver7.5.5 custom OS5
    415 ci
    239/255 .624 lift LSr grind
    16psi
    Meth injection
    PLX WB02

  8. #8
    Senior Member exploder's Avatar
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    I also noticed something else funny while doing all of this. The commanded idle is somewhere around 1900rpm, but the idle never even gets close to that even when I'm helping it by giving it a little throttle.
    03 z06 auto
    ver7.5.5 custom OS5
    415 ci
    239/255 .624 lift LSr grind
    16psi
    Meth injection
    PLX WB02

  9. #9
    Senior Member exploder's Avatar
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    I think I fixed it. I upgraded to an 02 model OS and it gave me alot more resolution as far as Idle Air Flow. I got it to startup now is there any way to migrate all of my other tune stuff into this without having to do a compare and manually change them all?
    03 z06 auto
    ver7.5.5 custom OS5
    415 ci
    239/255 .624 lift LSr grind
    16psi
    Meth injection
    PLX WB02

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