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Thread: LSA Swap tuning challanges

  1. #1
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    LSA Swap tuning challanges

    Really looking for some advice and direction here. I have a 2009 Pontiac G8 GT that I did an LSA swap on. Factory otherwise, and Factory LSA components (LSA injectors, CTSV MAF, GM ZL1 3 bar, ZL1 lid)

    Attached is a tune I'm working on. I'm very new to all this and learning as i go so I apologize in advance haha.

    I took my factory tune, converted it to a 2 bar map and have tried coping much of the data from a Stock CTSV and even Matt Hapels LSA 4.8 and I keep getting the same result. A real clean cold start that revs to 2000 RPM and after a few seconds the RPM plummets and dies. Attached is the tune with data focused around a stock CTSV.

    Any advice and input would be greatly appreciated. I'm trying to get the car to point where it can idle and move around. I know it will run as I had it going on a 1 bar tune and it idled really well. I just cannot seem to make the jump to a 2 bar configuration.

    -Thanks
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  2. #2
    Tuning Addict 5FDP's Avatar
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    The MAF is set to be disabled, is that someone you are trying to do?
    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
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    ah, no- I tried to do that to play with the VE and forgot to change it back. That did improve it, it tries to correct itself when it drops now (around 800 rpm) but ultimately dies out. Thanks for catching that.

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    Any other ideas? sorry to be a bug.

  5. #5
    Tuning Addict 5FDP's Avatar
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    Without a log I don't know what it's doing.

    I surely wouldn't have copied over everything from the 4.8 tune you did gather information from. I would have brought over the stock VVE data into the new VE tables using an excel program as that is going to be the correct fueling data compared to a 4.8 LSA tune.
    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.

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    Under the Idle->RPM tab, look at the Proportional and Integral Airlow and Airflow limits. Try increasing the values for negative RPM deltas by some percentage factor. My tune uses "normal" values in those tables that are about twice what I see in yours. On the Idle->Airflow tab, look at the Final Airflow Minimums. Mine are about 50% greater than yours. On my first few tunes, my engine would often stall after failing to recover from a quick throttle blip or trying to gently back out of my garage. Increasing the minimum idle airflow and minimum idle RPM helped eliminate that misbehavior for me. As always, YMMV!
    Last edited by pannetron; 03-09-2020 at 10:30 PM.

  7. #7
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    Okay, so- I made a quick log. The car kept running, very poorly for this log. After this I couldn't get the car to continue running but it does what I mentioned before- fires up strong then just dies out.

    The options im logging were recommended by a video i was watching on tuning. If these are the wrong variables to be monitoring can you please tell me what you need me to be logging? Sorry for the delay on this, i wanted to hook up my wideband so that wasnt the immediate next hurtle.

    Also! Pannetron, thanks for chiming in- I modified those tables to reference the ctsv but now that I re-read your reply i'm questioning if those variables pushed further in the wrong direction. I've re-attached my modified tune for clarification.

    -Thanks for all the help so far!
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  8. #8
    Tuning Addict 5FDP's Avatar
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    You're missing a decent amount of things in the log still. Like engine rpm, o2 sensors trims, throttle percent. You are logging the 1 bar MAP sensor channel, see if you can find the 3 bar MAP sensor channel.

    This log shows that the MAF sensor is not there but the tune file shows that the MAF has not been failed correctly yet. If you are not running the MAF sensor, then you still need to fail the MAF within the tune file.

    But if you are running the MAF, you need to get that working and put a few of the settings back so that it can use the MAF to run.
    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.

  9. #9
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    From that log it looks like your O2 sensors may be disconnected. Also, if the commanded AFR is correct, your computer is trying to command a pig rich AFR.

  10. #10
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    Quote Originally Posted by 5FDP View Post
    You're missing a decent amount of things in the log still. Like engine rpm, o2 sensors trims, throttle percent. You are logging the 1 bar MAP sensor channel, see if you can find the 3 bar MAP sensor channel.

    This log shows that the MAF sensor is not there but the tune file shows that the MAF has not been failed correctly yet. If you are not running the MAF sensor, then you still need to fail the MAF within the tune file.

    But if you are running the MAF, you need to get that working and put a few of the settings back so that it can use the MAF to run.


    Hmmm, okay- slowly but surely. I fixed the logging items. I cant seem to figure out what I did to the MAF though, I thought I fixed all the settings but its still showing 0 hz in the scanner. Ill have to compare old tune files, I'm looking under Engine > Airflow and Diag > Airflow correct? It looks like p01001-3 are enabled too.

  11. #11
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    You have applied a 2 Bar COS to the PCM, so I think it should automatically disable the MAF.
    Let's try adding 20% fuel to the VE table and see if that gets you to a better start.
    Try this one and give us a datalog.
    G8stocktune2009_CMtune_TRYME_2barV3.hpt

  12. #12
    Tuning Addict 5FDP's Avatar
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    The MAF still functions like normal on upgraded OS's. It's up to user to still use it.

    In the recent tune file he had the Dynamic airflow settings set at like 8,000rpm so it would be speed density but the MAF fail settings remained stock, so that part wasn't correct if speed density only was wanted. The other part being that the MAF wasn't reporting at all in the log but it seemed he wanted to use it.
    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.

  13. #13
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    Quote Originally Posted by 5FDP View Post
    The MAF still functions like normal on upgraded OS's. It's up to user to still use it.

    In the recent tune file he had the Dynamic airflow settings set at like 8,000rpm so it would be speed density but the MAF fail settings remained stock, so that part wasn't correct if speed density only was wanted. The other part being that the MAF wasn't reporting at all in the log but it seemed he wanted to use it.
    Thanks for the info! I don't think I've ever tried using the MAF with a 2 bar OS.

  14. #14
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    Sorry, admittedly the tune file may be a little messy from me trying different things from various videos I'm watching and not saving enough revisions.I'm really just trying to get it to idle so I can begin these various tuning practices I'm learning about. Which, will include saving a tune file every small change. So, again sorry if me being messy in the start here is making it more difficult to help me.

    Should I just be disabling MAF and focusing on speed density? I know you said previously its up to the user but I'm not sure if I should be eliminating functions for a more streamline cold start?

  15. #15
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    Quote Originally Posted by kevin87turbot View Post
    You have applied a 2 Bar COS to the PCM, so I think it should automatically disable the MAF.
    Let's try adding 20% fuel to the VE table and see if that gets you to a better start.
    Try this one and give us a datalog.
    G8stocktune2009_CMtune_TRYME_2barV3.hpt

    Kevin, Thanks for chiming in! It feels closer. Re-attached is the log and tune file, I did go into the tune and (I believe) Re-enable MAF.

    Can you or 5FDP confirm, is MAF now enabled? More importantly, should it be disabled?

    -Thanks again!
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