Results 1 to 13 of 13

Thread: 2017 mustang speed density only no maf Fuel leans out when going to PE

  1. #1
    Tuner in Training
    Join Date
    Aug 2019
    Posts
    26

    2017 mustang speed density only no maf Fuel leans out when going to PE

    Hey everyone,

    Having an issue with fuel going super lean after going into PE before 4k rpm. It will stutter and pop when this happens then take off. I have a test tune im running where i disabled fuel cut torque ratio and removed torque limits, disabled tip in and anti shuffle. Car is a 2017 mustang 3.7 with long tube headers and mu52 injectors. Any help would be greatly appreciated in pointing me in the right direction.

    Fuel cut torque disabled-anti shuffle off.hpt
    21-12-05 11-36-05.hpl

  2. #2
    Potential Tuner
    Join Date
    Dec 2020
    Posts
    4
    Quote Originally Posted by Mercilus View Post
    Hey everyone,

    Having an issue with fuel going super lean after going into PE before 4k rpm. It will stutter and pop when this happens then take off. I have a test tune im running where i disabled fuel cut torque ratio and removed torque limits, disabled tip in and anti shuffle. Car is a 2017 mustang 3.7 with long tube headers and mu52 injectors. Any help would be greatly appreciated in pointing me in the right direction.

    Fuel cut torque disabled-anti shuffle off.hpt
    21-12-05 11-36-05.hpl
    I am somewhat new to HP tuners but come from the world of Standalone EFI systems. I took a precursory look at your tune and log. In the log I didnt see any 02 voltages in the log. in the tune I looked at parameters to enter PE and noticed that 90 percent throttle was needed to enter. On a standalone speed density system when it has a lean stumble it is due to not enough acceleration fuel enrichment. A Map sensor car struggles with a sudden opening of the throttle body and requires a extra squirt of transient fuel to overcome the sudden lean condition.

  3. #3
    Advanced Tuner
    Join Date
    Jun 2020
    Posts
    775
    How did you disable fuel cut torque ratio?

  4. #4
    Senior Tuner SultanHassanMasTuning's Avatar
    Join Date
    Nov 2009
    Location
    All Around
    Posts
    3,149
    torque management tab
    Follow @MASTUNING visit www.mastuned.com
    Remote Tuning [email protected]
    Contact/Whatsapp +966555366161

  5. #5
    Senior Tuner
    Join Date
    Jan 2013
    Location
    Hawaii
    Posts
    2,101
    For MU52's, use the injector data from the 13-14 GT500's.

    13-14 GT500 injector data.jpg

  6. #6
    Advanced Tuner
    Join Date
    Jun 2020
    Posts
    775
    Quote Originally Posted by SultanHassanMasTuning View Post
    torque management tab
    That’s not what I’m asking.

  7. #7
    Advanced Tuner
    Join Date
    Jun 2020
    Posts
    775
    Dumb question, does the 3.7 have a map sensor?

  8. #8
    Senior Tuner SultanHassanMasTuning's Avatar
    Join Date
    Nov 2009
    Location
    All Around
    Posts
    3,149
    yes no more maf on S550 body v6
    Follow @MASTUNING visit www.mastuned.com
    Remote Tuning [email protected]
    Contact/Whatsapp +966555366161

  9. #9
    Tuner in Training
    Join Date
    Aug 2019
    Posts
    26
    If you go to torqu management fuel cut you can tell it what to disable by changing the numerical value to 0. you dont want to turn it all off as it can effect decel and cause weird issues so i selected all the stuff that could possibly be interfering with fueling and set to 0

  10. #10
    Tuner in Training
    Join Date
    Aug 2019
    Posts
    26
    Quote Originally Posted by murfie View Post
    For MU52's, use the injector data from the 13-14 GT500's.

    13-14 GT500 injector data.jpg
    i switched to the gt500 data. I did find tho that nothing was gonna fix my bad fuel pump lol. so now its on a dw400 pump and is running amazing. i need to dial in the fueling now as my trims are pretty high but im on stock transport delays and longtube headers so im gonna start working on that and speed denstity tuning once i finish my vct tuning.

  11. #11
    Tuner in Training
    Join Date
    Aug 2019
    Posts
    26
    Quote Originally Posted by Swampmonster View Post
    I am somewhat new to HP tuners but come from the world of Standalone EFI systems. I took a precursory look at your tune and log. In the log I didnt see any 02 voltages in the log. in the tune I looked at parameters to enter PE and noticed that 90 percent throttle was needed to enter. On a standalone speed density system when it has a lean stumble it is due to not enough acceleration fuel enrichment. A Map sensor car struggles with a sudden opening of the throttle body and requires a extra squirt of transient fuel to overcome the sudden lean condition.
    yes that is correct. one of my test tunes i had i increased my transient and i increased the enrichment rate from .250 to .350 and saw it run leaner. It did turn out to be a fuel pump tho so now im dialing it all back in with a good pump.

  12. #12
    Advanced Tuner
    Join Date
    Jun 2020
    Posts
    775
    Ok that’s why I asked. When you set the fuel cut torque ratio to zero then you are allowing enleanment. This whole table is typically set to 1.0 so it skips enleanment and goes straight to cylinder cut. I’ve tested this myself and found it to be true.

    I don’t like how HPTuners describes describes this table. I think it should be called the “enleanment torque ratio limit”, because it doesn’t allow or disallow cylinder fuel cut. First is spark, then enleanment, then cut. For instance, if spark tr and enleanment tr are both 1.0 then it goes straight to cut.
    Last edited by engineermike; 12-09-2021 at 10:17 AM.

  13. #13
    Tuner in Training
    Join Date
    Aug 2019
    Posts
    26
    Just wanted to say Thank you to everyone that responded.