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Thread: Opinions please?

  1. #1
    Tuner in Training
    Join Date
    May 2020
    Location
    Casper, Wy
    Posts
    17

    Opinions please?

    Hey there fellas!
    So this is my first ever go at tuning fuel injection and I feel like I've done a fairly decent job at it. I do know there are still some tweaks I need to do in the tune and currently I am making tweaks to my timing and VE tables. I have my fuel trims disabled and open/closed loop disabled also, as I seem to be having an issue with my bank 2 O2 sensor, it swings up and down from the bottom of its range to the top of its range in a matter of seconds(over and over, nonstop) and it throws my afr/trims way off. Another issue I am aware of is my STIT is off in gear, which I haven't been able to fix by adding air to my BRAF. I gave up on that for the short term and will come back to it later as it starts and idles pretty damn good and doesn't have any cruise/hanging idle issues.
    I am posting this in hopes that I can get some of the guys that actually do this stuff for a living (or the ones that are just dang good at this stuff!!) to look at this log and my tune and critique it. Tell me how I am doing, maybe what I am doing wrong, etc, etc. Criticism is definitely welcome! I am aware that my afr error histogram had some lean areas. I have already applied the changes to my tune, which is the tune that I am posting. I have been struggling a bit with getting my VE table/afr to remain stable from drive to drive. I make a change and it seems to do good, then I get in at a later time to drive it and it is almost like I did more revisions, except I didn't.
    One thing that I am trying to get an answer to is why my bank 2 O2 sensor swings wildly like it does. I have done a ton of research and can't seem to find an answer. I am also having a bit of an issue with the car running lean right after I fire it up for a minute or 3, then once i hit the throttle or drive it a minute, it settles in and goes to where it should.
    Like I said, I welcome any criticism, in fact, look forward to it!
    Thanks everyone,
    Anthony.

    P.S. I live in the middle of Wyoming and do not have a very good selection of tuners to be able to take a peek at my tune, so I am, more or less, relying on your criticism to help me perfect this. Thanks again!
    Attached Files Attached Files

  2. #2
    Tuner in Training
    Join Date
    May 2020
    Location
    Casper, Wy
    Posts
    17
    I now have open loop enabled as I read some more and learned that it has fuel corrections that will help with my lean conditions on startup

  3. #3
    Advanced Tuner
    Join Date
    Jun 2015
    Posts
    253
    open loop is where it uses what ever fueling it has in the tune without any feedback from the o2 sensors. Closed loop is where it uses the o2 sensors that are either reading rich or lean from stoich and it adjusts based off of those. You have long term and short term fuel trims that it will can add together to try to get the commanded afr if your not in power enrichment. When you are in power enrichment they won't be giving any feedback.

  4. #4
    Tuner in Training
    Join Date
    May 2020
    Location
    Casper, Wy
    Posts
    17
    Quote Originally Posted by ryan_axberg View Post
    open loop is where it uses what ever fueling it has in the tune without any feedback from the o2 sensors. Closed loop is where it uses the o2 sensors that are either reading rich or lean from stoich and it adjusts based off of those. You have long term and short term fuel trims that it will can add together to try to get the commanded afr if your not in power enrichment. When you are in power enrichment they won't be giving any feedback.
    Yes, I understand that, especially now that I have done a bunch more reading into open loop. For some reason I was under the impression that open loop also used the o2 sensors, and that is why I had it all turned off. My issue with the sensor is stated in my original post(which I am still trying to get some light shed on why the sensor is acting that way). No matter really if I can't find out why. I am going to replace it with a new or used/known working one to see if it is just the sensor itself. If it isn't, I also have a set of flex fuel injectors that I am going to install very soon(as well as an LS1 intake mani so I can finally put my hood back on!), which will help me rule out injectors as a possible cause.


    I was really hoping to be able to get some feedback on my tune. This forum feels like a ghost town, especially given how many people use this platform to tune their LS engines. Pretty disappointing.