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Thread: Cold idle/drive stumbles, warm is mostly

  1. #1
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    Default Cold idle/drive stumbles, warm is mostly fine

    01 LS1, LS6 Intake, 224R Cam, Long tubes

    I went through the standard Calc.VET tuning for my driving and, outside of an occasional stall when coming to a stop here and there, it drives great. My problem is the cold idle/drive, I'm not sure where to go on getting that tuned to where I don't have to sit in my car for 5-10 minutes just idling (sometimes having to hold the gas a bit) to keep it from dying, or try and shift under ~1.5k rpms to prevent it from stumbling. Any potential insight would be great.
    Last edited by tenpaiyomi; July 23rd, 2016 at 12:28 AM.

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    Default Cold idle/drive stumbles, warm is mostly

    A tune and log would help. You may need to add some air to your desired airflow and perform a rafig/rafpn. Once you do that, take a look at the throttle follower values.
    Last edited by LastCall; July 23rd, 2016 at 08:57 AM.
    00 Silverado Z71, LQ9 w/ LS3 heads, BTR cam, Whipple 2.9@8#, 4l80E

  3. #3
    Joe (Moderator) joecar's Avatar
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    +1 what LastCall said.

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    Yep, I'll get the tune/log as soon as possible. What sort of log are you guys wanting, just a general startup until it's warm? Any particular PIDs you want me to monitor? I'm not familiar with rafig/rafpn, can you explain on that?

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    The rafpn and rafig are calculated pids that measure the correction applied by short and long term idle trims. Right clicking on them will tell you the other pids required to make them work properly. You'll also need the map so you can apply the values to the desired airflow table. Other pids I would log are iac steps, rpm, dynclyair, timing, iat, and ect.
    00 Silverado Z71, LQ9 w/ LS3 heads, BTR cam, Whipple 2.9@8#, 4l80E

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    Quote Originally Posted by LastCall View Post
    The rafpn and rafig are calculated pids that measure the correction applied by short and long term idle trims. Right clicking on them will tell you the other pids required to make them work properly. You'll also need the map so you can apply the values to the desired airflow table. Other pids I would log are iac steps, rpm, dynclyair, timing, iat, and ect.
    Thanks for the explanation on that. I've got RAFPN, RAFIG, MAP, IAC, RPM, DYNCLAIR, IAT and ECT. Only thing I'm a little unsure of is timing, not really sure which PID it is. My guess off hand is EST_RUN_DMA, but wanted to confirm before I do some logs.

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    Should be timing advance for cylinder 1. Add in TPS, MAF airflow, and and long term fuel trims.
    00 Silverado Z71, LQ9 w/ LS3 heads, BTR cam, Whipple 2.9@8#, 4l80E

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    Quote Originally Posted by LastCall View Post
    Should be timing advance for cylinder 1. Add in TPS, MAF airflow, and and long term fuel trims.
    Currently running an SD tune, so no MAF right now. I can add all the others though and get the log. If MAF is absolutely needed, I can swap back to non-SD and put the MAF back on.

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    Log and tune. This is from cold to normal operating temperature when my fans turn on. Any help is greatly appreciated!

    Modified.ctz
    ColdIdleLog.efi

  10. #10
    Joe (Moderator) joecar's Avatar
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    Quote Originally Posted by tenpaiyomi View Post
    Thanks for the explanation on that. I've got RAFPN, RAFIG, MAP, IAC, RPM, DYNCLAIR, IAT and ECT. Only thing I'm a little unsure of is timing, not really sure which PID it is. My guess off hand is EST_RUN_DMA, but wanted to confirm before I do some logs.
    Timing pid is SAE.SPARKADV.

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