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Thread: Need help with idle issue when shifing.....

  1. #1
    Tuner in Training clshortt1's Avatar
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    Need help with idle issue when shifing.....

    Tuning a P59 in a rock crawler. Been fighting with this for some time. Engine is a stock 5.3 with mild-medium cam. 400 Turbo trans and stock converter. Still tuning in speed density mode. MAF disabled, STFT and LTFT disabled, Getting close on the VE table. Tuning with AEM wideband coming through the AC pressure sensor. Torque management disabled.
    This issue I'm having is this; when going from park to any gear (R or D) my rpm drop to almost nothing and then surges back to stable. Going from in-gear to park, idle surges up and then stabilizes. Going from R to 3, almost dies and then surges up, lurching the jeep in whatever gear i went into.
    I can't for the life of me get this fixed! Can someone take at look at this tune and give me some ideas? Thanks so much for your help!



    Crawler Tune LS ECM - 3.7.8.hpt

  2. #2
    Tuning Addict 5FDP's Avatar
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    Does a higher idle make it any different?

    What about adjustments to the idle airflow?
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  3. #3
    Tuner in Training clshortt1's Avatar
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    I have tried both of those changes. Neither seemed to help.

    I can post a video with the scanner if that would help.

  4. #4
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    Depending on your cam choice that stock converter might just be too tight. While nobody wants to rip the car all apart to change out the converter, it might be the only way you'll really fix that.

  5. #5
    Tuner in Training clshortt1's Avatar
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    Well, I see what your saying and I wondered about that myself. The only thing is this, the motor I pulled out was a '97 Vortech 5.7 and it did not have this problem. Surely there is something I can do. It's almost like it is not reacting quick enough.
    One thing I forgot to mention is that I equipped the shifter with switches that tell the ECM weather it's in PN or in Gear. So it knows whrn I'm shifting it.

  6. #6
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    disable burst knock
    disable stall saver.

    perform a write entire to actually apply the SD custom OS and run correctly with no MAF.

    confirm idle afr isnt too rich or lean. 13.2-14.5 AFR with a cam is fine. some prefer being a little rich others not.

    then use timing and air. you need to set it up to idle in P/N at 8-10 degrees spark. this will likely require you to increase the throttle blade stopper to add more air at idle and then reset the 0%TPS position. once this is achieved. command 18-25 degrees spark in gear.

    set idle spark tables to have lower values above target idle rpm and higher below as best as possible with resolution provided. plus the idle spark correction will help.

  7. #7
    Tuner in Training clshortt1's Avatar
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    Lukearmstrong1990,

    Thank you for the reply. This gives me some good things to try. What is meant by "SD custom OS" Can you enlighten me more on this?

    I'll check the idle AFR again. It has been really close every time I've logged it. I may set it a little richer.

    I'll adjust the P/N timing to your suggestion and leave the in-gear set where it is (20-25 I think). I'm running a drive-by-wire throttle body so there is no blade stopper.

    I'll try the idle timing ideas and post back how they work.

    Thanks again for the help!

    Edit...

    DUH!!! Figured out SD custom OS - Speed Density....and Operating System.....Covid Coop-Up rotting my brain.....
    Last edited by clshortt1; 04-02-2020 at 10:30 AM.

  8. #8
    Tuner in Training clshortt1's Avatar
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    Exclamation UPDATE - converter installed

    UPDATE -- Still need help!!
    Okay, I installed a B&M 2400 stall converter to loosen up the trans at idle. NO MOSS!! Still have the SAME problem. I am about ready to give up. I have no idea what is going on. I have tried a hundred different things and nothing seems to make a difference. It seems to do better when the engine is cold, but the more it warms up, the worse it gets. It's to the point it will die almost every time I go from drive to reverse, or from park to any gear. I've posted my most current attempt at fixing it.
    I'm at a total loss at this point. Can someone give me some insight please? Thanks.

    One thing I forgot to mention is it does not do this when it's cold. Shifts perfectly then.

    Crawler Tune LS ECM - 3.7.31.hpt
    Last edited by clshortt1; 05-09-2020 at 10:40 AM. Reason: added more information

  9. #9
    Tuning Addict 5FDP's Avatar
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    Did you try the stall saver disable to see if that helped at all??

    I hope those PE settings are just for testing, you don't want PE disabled like that.

    I also think your base running airflow tables might be a little suspect. It's a stock 5.3 and I compared to a different stock 5.3 file and your numbers are higher. I would also remove all that negative timing in the high/low table at those low rpm high cylinder airmass values.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  10. #10
    Tuner in Training clshortt1's Avatar
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    5FDP,
    Yes, it's just for testing. I could not figure out how to disable the stall saver. If you wil let me know the correct way to do that, I'll try it now and let you know the results. I'm still trying to dial in the VE table but with it idling like this, it's very hard to drive. This is also a non-street legal built Jeep, but I fortunately I can drive it around the neighborhood. This is a stock 5.3 with a somewhat mild cam.

    Here are the cam numbers;

    1997-2004 GM LS Series (Gen III)
    Lift: 0.523"/0.524"
    Duration @ 0.050": 218?/227?
    Advertised Duration: 278?/287?
    Lobe Separation: 112?
    RPM Range: Idle-5,000 RPM

  11. #11
    Tuner in Training clshortt1's Avatar
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    5FDP....don't leave me hangin' man. I'm die'n on the vine here.....:-)