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Thread: Stuck on start up issue

  1. #1
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    Stuck on start up issue

    So I have been slowing working through tuning this thing. Now I have an RPM swing on start up but only during the " start up" sequence. The 90 seconds it idles high before it idles down is the only time it does this. Any suggestions would be appreciated
    The current tune and log is attached. Cold start and a hot start at the end of the log. Currently running in OL, Fuel trims at start up are low 14.xx

    June 1 HRT Jeep.hptjune one start log cold -hot.hpl

    Thanks

  2. #2
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    I remember you posted on my thread of the exact same issue .I?m still having the same issue so if you get your resolved i?d love to hear how they fixed it .. I have a 1,400 rpm high idle and slowly drops down no matter if it?s hot or cold

  3. #3
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    I gave up on that problem. Now I get more of a surge but just in that first 90 seconds.

  4. #4
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    yeah it looks like it has a radical cam

    especially when warm

    something in the airflow is off but weird how it goes away

  5. #5
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    Its got an HRT stage 2 cam.
    So far I added fuel to the FA cold start table and it made it a bit better but still needs help somewhere. I am assuming the air flow tables.

  6. #6
    Advanced Tuner f.creek-ranch's Avatar
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    didnt look at the log yet.
    But isnt it so, that the ann takes over at 12 sek and use the adapted values for fuel trims ? the gpec2 do so.

  7. #7
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    This is the much older NGC4 so no NN...

  8. #8
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    it uses open and closed loop tho

  9. #9
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    Definitely a fueling issue...
    2016 Ram CCSB Forged NA 396ci Stroker
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  10. #10
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    Your manifold pressure seems to be relatively steady throughout. But your fuel mass, injector pulse widths, and both bank's sensor 1 O2 sensors are all going ape sh*t right from the start. Might look at your part throttle spark table as well, mainly the transitioning from 55 to 60 Kpa range and vice versa in your idling columns.
    2016 Ram CCSB Forged NA 396ci Stroker
    +1.5cc Flat top Mahle Power-Pak Forged Pistons w/13.2/1 CR on E85
    Forged Manley 4.05" Stroke Crank
    Race Ported Eagles/Titanium 2.10"/Titanium 1.62" Valves
    Self-Designed Custom Grind 236/249 .629/.629 111LSA 110ICL+1Adv
    Ported Holley Hi-Ram Intake/NXpress Hi-Ram NO2 Plate kit w/250 Shot(4 sec)
    Tx Spd 2" Prim LT Headers/Active Viper Hood/2-Step Launch
    ATI SD w/15% UD/Hellcat Pump/Demon 700cc Inj
    Edge Pro Conv w/3800 stall/Det Tru-Trac/410 Gears

  11. #11
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    Quote Originally Posted by Spray-Cam Hell-Ram View Post
    Your manifold pressure seems to be relatively steady throughout. But your fuel mass, injector pulse widths, and both bank's sensor 1 O2 sensors are all going ape sh*t right from the start. Might look at your part throttle spark table as well, mainly the transitioning from 55 to 60 Kpa range and vice versa in your idling columns.
    Shoot ya I forgot I put a big dip in the timing there, that was an experiment for a different issue and I missed putting it back. However the O2s have been all over the place for quite some time, I assumed it was because of the lumpy cam and choppy ish idle timing....

  12. #12
    Potential Tuner
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    its program to do that look in ecm 35573 base set point you can adjust from there

  13. #13
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    Quote Originally Posted by fastrt09 View Post
    its program to do that look in ecm 35573 base set point you can adjust from there
    Table not available on NGC4..

  14. #14
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    So start up rpm swing/surge is better after adjusting start up air flow and fixing my pt spark table. Air flow made the biggest change. B1 and B2 sensors are still weird at the 70 ish second point of run time then go more normal once I started driving. I think maybe because engine is still cold and a bit rich its messing with the sensors until everything is hot




    June 6 cold strt and log.hpl
    june 6 fix.hpt

  15. #15
    Advanced Tuner f.creek-ranch's Avatar
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    Torque or airflow settings….not to forget….

  16. #16
    Advanced Tuner PurpleRam's Avatar
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    Quote Originally Posted by f.creek-ranch View Post
    Torque or airflow settings….not to forget….
    They’re out of wack on the ngc to start
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  17. #17
    I have a similar issue since swapping to e85 in my hellcat with the injectors to support it. First 90 seconds the car surges its brains out until it gets to closed loop fueling then it idles like its stock. Should I add start up airflow or fuel? havent played with either yet