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Thread: Need some help w/ maf tuning

  1. #1
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    Need some help w/ maf tuning

    16-08-17 07-29-30.hpl I have added % to the Maf table and it leans out ? Please let me know what I'm doing wrong.

  2. #2
    Senior Tuner mbray01's Avatar
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    well first off, your logging wideband with fuel trims still enabled, you need to be in open loop
    Michael Bray
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    No reason you can't use fuel trims for part throttle and WB for WOT.

    I don't see anything lean in that log though.

    Most of the part throttle areas of that log have - fuel trims, which means without them it would be RICH, so you need to reduce the MAF table, not increase them. That is assuming it's even in MAF only mode. Without a tune to look at who knows.

    The WOT sections are not far off though best I can tell.
    Post a log and tune if you want help

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    Senior Tuner mbray01's Avatar
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    I assume he's using afr error to make corrections, but fuel trims are still enbled. I guess he needs to specify if he is using afr error, or fuel trims to tune with
    Michael Bray
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  5. #5
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    Quote Originally Posted by schpenxel View Post
    No reason you can't use fuel trims for part throttle and WB for WOT.

    I don't see anything lean in that log though.

    Most of the part throttle areas of that log have - fuel trims, which means without them it would be RICH, so you need to reduce the MAF table, not increase them. That is assuming it's even in MAF only mode. Without a tune to look at who knows.

    The WOT sections are not far off though best I can tell.
    Here's the tune. I'm new to this so don't beat me up too bad. Thanks for your help guys

  6. #6
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    I don't see anything obviously horrible

    Just keep working fuel trims down. I wanted to make sure you were going the right way.. if they're negative then you want to reduce MAF/VE tables

    Also keep in mind you typically want to be in MAF only or SD (VE) while tuning. Otherwise you don't know whether you should be adjusting the MAF or VE tables. Disable MAF, tune VE. Switch to MAF only, tune MAF. Re-enable both or whichever you prefer.

    Current tune looks to be in mixed mode, both MAF and VE are active

  7. #7
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    Quote Originally Posted by schpenxel View Post
    I don't see anything obviously horrible

    Just keep working fuel trims down. I wanted to make sure you were going the right way.. if they're negative then you want to reduce MAF/VE tables

    Also keep in mind you typically want to be in MAF only or SD (VE) while tuning. Otherwise you don't know whether you should be adjusting the MAF or VE tables. Disable MAF, tune VE. Switch to MAF only, tune MAF. Re-enable both or whichever you prefer.

    Current tune looks to be in mixed mode, both MAF and VE are active
    Where exactly do you enable /disable these ? Thanks for your replies! I'm greatful

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    To set to MAF only you will set dynamic airflow disable to low RPM's. It's under engine, airflow, dynamic. Set to something like 200 and 100

    To set to SD only you want to fail the MAF entirely by setting the high frequency limit to something really low. It's under engine diag, airflow. Set the high freq limit to something like 1hz

    Going from memory here so names might be slightly different but you should find them

  9. #9
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    Quote Originally Posted by schpenxel View Post
    To set to MAF only you will set dynamic airflow disable to low RPM's. It's under engine, airflow, dynamic. Set to something like 200 and 100

    To set to SD only you want to fail the MAF entirely by setting the high frequency limit to something really low. It's under engine diag, airflow. Set the high freq limit to something like 1hz

    Going from memory here so names might be slightly different but you should find them
    Thanks again, I'll get on that.

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    Disable DFCO when logging, Fuel-->Cutoff/DFCO set enable /disable temp to max. DFCO can be filtered out of the log also. PE commanded is rich like boosted rich, this is ok for dialing in but wouldn't leave it there. How big is the stg3 cam mid to high 230's? When dialling in the maf look at the shape of your stock curve, try to keep a similar shape. I'm getting a bit off topic, just some things in the tune look a bit weird to me.

  11. #11
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    Quote Originally Posted by Codes View Post
    Disable DFCO when logging, Fuel-->Cutoff/DFCO set enable /disable temp to max. DFCO can be filtered out of the log also. PE commanded is rich like boosted rich, this is ok for dialing in but wouldn't leave it there. How big is the stg3 cam mid to high 230's? When dialling in the maf look at the shape of your stock curve, try to keep a similar shape. I'm getting a bit off topic, just some things in the tune look a bit weird to me.
    Thanks for the reply. I haven't touched the commanded PE yet. I am open to suggestions on what it should be and how to do that.
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  12. #12
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    For VE mode... Fail Your Maf by setting the Frequncy Fail High to 0 htz ... Eng Diag>Airflow>Mass Airflow Sensor .. Then in DTC set all three MAF sensor (P0101,102,0103) to Mil's on One. Set DFCO Enable Temp to 350 Deg. Engine>Cutoff,DFCO>DFCO Enable Normal.....Power Enrichment Hot and Cold to 100 across the board..Engine>Power Enrich> PE Throttle/Pedal, Disable CAT Overtemp Protection... Engine>COT, Lean Cruise> COT -Disabled... You should now be in VE only Mode... Ater you have made your adjustment within +/- 3% to the primary VE table.. You can transition to Maf only... Turn the Maf Htz and Maf DTC'S to their original setting, and then set your Dynamic Airflow High RPM Disable to a low number like 200 RPM... Engine>Airflow>Dynamic> High RPM Disable...Now you should be in Maf Only Mode. When you are done adjusting the Maf Fuel trims...Set ALL the Parameters, COT, High RPM Cut Off, PE Throttle/Pedal,Etc back to their original settings.... Good Luck...

  13. #13
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    Quote Originally Posted by Jggregory99 View Post
    For VE mode... Fail Your Maf by setting the Frequncy Fail High to 0 htz ... Eng Diag>Airflow>Mass Airflow Sensor .. Then in DTC set all three MAF sensor (P0101,102,0103) to Mil's on One. Set DFCO Enable Temp to 350 Deg. Engine>Cutoff,DFCO>DFCO Enable Normal.....Power Enrichment Hot and Cold to 100 across the board..Engine>Power Enrich> PE Throttle/Pedal, Disable CAT Overtemp Protection... Engine>COT, Lean Cruise> COT -Disabled... You should now be in VE only Mode... Ater you have made your adjustment within +/- 3% to the primary VE table.. You can transition to Maf only... Turn the Maf Htz and Maf DTC'S to their original setting, and then set your Dynamic Airflow High RPM Disable to a low number like 200 RPM... Engine>Airflow>Dynamic> High RPM Disable...Now you should be in Maf Only Mode. When you are done adjusting the Maf Fuel trims...Set ALL the Parameters, COT, High RPM Cut Off, PE Throttle/Pedal,Etc back to their original settings.... Good Luck...
    Does this mean I should be tuning the VVE first and the MAF second or does this really not matter ?

  14. #14
    I tuned my VVE first due to my cam swap and then on to my MAF as I was informed the VVE table is used as a reference. I used LTFT+ STFT as i couldn't get my wideband to work properly, i was able to get my LTFT to +- 3% through 4000RPM, and STFT to 2%. I recommend tuning all in the same day, I attempted to do it over a couple days (after work) and the temp difference made me chase my tail, but hey I'm new to this.