1. Join the Community!

    DSMtuners is a massive archive of DSM information - but more importantly, it's a COMMUNITY! Join in and participate with other DSMers, and invite all of your DSM friends to make this place their home. Chat with others, create a build thread, post questions and answers. Get involved! Logging in will also remove many of the advertisements, along with this notice. ;)

ECMlink Throttle tip in lean from idle

Posted by Jacob_Barnes520GST, Jul 23, 2020

Please Support STM Tuned
Please Support STM Tuned
  1. Jacob_Barnes520GST

    Jacob_Barnes520GST Proven Member

    100
    8
    Joined Feb 21, 2018
    Tucson, Arizona
    I'm having a hard time with throttle tip in. Whenever I step on the gas pedal from a 0% throttle position, I lean out badly for a second then it returns to normal AFR. I adjusted the BaseTipInTPSAdj in direct access and didn't help anything. I'm stumped if anyone can help I'd appreciate it. I will attach a log below.
     

    Attached Files:

    Street Build 584  8

    1995 Mitsubishi Eclipse GST
    fwd · automatic · 2G DSM
    Loading...
  2. jcastello214

    jcastello214 Proven Member

    91
    20
    Joined Jul 17, 2012
    Daly City, California
    Checked for boost leaks right?
     

    Street Build 735  0

    1994 Eagle Talon TSi AWD
    automatic · 1G DSM
    Loading...
  3. Jacob_Barnes520GST

    Jacob_Barnes520GST Proven Member

    100
    8
    Joined Feb 21, 2018
    Tucson, Arizona
    Yes. No boost leaks
     

    Street Build 584  8

    1995 Mitsubishi Eclipse GST
    fwd · automatic · 2G DSM
    Loading...
  4. 1990TSIAWDTALON

    1990TSIAWDTALON Moderator

    6,470
    2,762
    Joined Nov 14, 2013
    Independence, Kansas
    Your log "looks" a little rich. Your computer is pulling 12-16% fuel from the mix according to your Combined FT at idle. Maybe the "bog" you have is from being too rich. If you have the courage (you can always change this back), change your global to -50, save to ECU, and see if your CFT gets closer to zero. You may think it is to lean when you touch the gas but "maybe" its just too rich. Just a comment/suggestion.
     

    Street Build 5K  29

    1992 Eagle Talon TSi AWD
    14.74 @ 117.04 · 1G DSM

    1K  14

    1990 Mitsubishi Eclipse GSX
    awd · manual · 1G DSM

    793  18

    1967 Chevrolet Camaro RS
    rwd · automatic · Misc Vehicles

    Street Build 1K  7

    1998 Eagle Talon TSi
    fwd · manual · 2G DSM

    Street Build 6K  14  25

    1990 Eagle Talon TSi AWD
    13.620 @ 108.460 · 1G DSM
    Loading...
  5. 1990TSIAWDTALON

    1990TSIAWDTALON Moderator

    6,470
    2,762
    Joined Nov 14, 2013
    Independence, Kansas
    There is also one other thing, try reducing your deadtime (leave global alone) and watch your Combined FT. I would start lowering it (deadtime) and see if the CFT gets closer to zero. It will adjust your STFT at the same time.
     

    Street Build 5K  29

    1992 Eagle Talon TSi AWD
    14.74 @ 117.04 · 1G DSM

    1K  14

    1990 Mitsubishi Eclipse GSX
    awd · manual · 1G DSM

    793  18

    1967 Chevrolet Camaro RS
    rwd · automatic · Misc Vehicles

    Street Build 1K  7

    1998 Eagle Talon TSi
    fwd · manual · 2G DSM

    Street Build 6K  14  25

    1990 Eagle Talon TSi AWD
    13.620 @ 108.460 · 1G DSM
    Loading...
  6. jakelandry

    jakelandry Proven Member

    897
    112
    Joined Oct 13, 2009
    Minden, Louisiana
    Admittedly, I did not look at your log, but “tip in” is a term that’s thrown around all too frequently. 9/10 tunes hesitate, stutter, bog, spike, etc. from the fuel and airflow being scaled out of proportion, not from a tip in setting. People regularly ask me to look at their tune cause they can’t get the “tip in” to act right. It’s usually the ve table having large jumps between cells or the wrong injector data and having a scenario of, in an exaggerated sense, “ twice the injector size half the VE” cause it yields the afr you want.
     

    4K  0

    1995 Mitsubishi Eclipse GSX
    11.410 @ 125.490 · 2G DSM
    Loading...
    1990TSIAWDTALON likes this.
  7. jed344

    jed344 Supporting VIP

    862
    111
    Joined Jan 10, 2008
    Waterville, Iowa
    100% correct. Tuned a car last weekend that had a stumble off idle. Car would go rich and die. After lowering SD to bring air flow per rev in check and fuel trims to within 5% problem solved.
     

    1K  38

    1997 Mitsubishi Eclipse GSX
    awd · manual · 2G DSM
    Loading...
    jakelandry and 1990TSIAWDTALON like this.
  8. jakelandry

    jakelandry Proven Member

    897
    112
    Joined Oct 13, 2009
    Minden, Louisiana
    I generally find that getting airflowperrev and fuel trims in check usually yields the best results. I have had the intention of writing a post explaining the basics of tuning for quite some time. I know there have been hundreds of posts but I firmly believe in understanding why you’re making the changes you make to the tune rather than what changes to make. Until I take the time to sit down and explain it, I recommend finding Kevin jewer’s account on the link forums and reading all of his posts. In the years I’ve been tuning I haven’t found anyone else who is willing to explain things to the extent he does, including the logic behind his methods.
     

    4K  0

    1995 Mitsubishi Eclipse GSX
    11.410 @ 125.490 · 2G DSM
    Loading...
    CAM280, 1990TSIAWDTALON and jed344 like this.
  9. jed344

    jed344 Supporting VIP

    862
    111
    Joined Jan 10, 2008
    Waterville, Iowa
    I have thought as well about. Sometimes what you think the car wants by looking at the wide band when car is in closed loop will steer you wrong and it may confuse new people.
     

    1K  38

    1997 Mitsubishi Eclipse GSX
    awd · manual · 2G DSM
    Loading...
  10. 1990TSIAWDTALON

    1990TSIAWDTALON Moderator

    6,470
    2,762
    Joined Nov 14, 2013
    Independence, Kansas
    WELL SAID!!! The only one to explain WHY! A super person to follow and read his post's, they are really invaluable.
     

    Street Build 5K  29

    1992 Eagle Talon TSi AWD
    14.74 @ 117.04 · 1G DSM

    1K  14

    1990 Mitsubishi Eclipse GSX
    awd · manual · 1G DSM

    793  18

    1967 Chevrolet Camaro RS
    rwd · automatic · Misc Vehicles

    Street Build 1K  7

    1998 Eagle Talon TSi
    fwd · manual · 2G DSM

    Street Build 6K  14  25

    1990 Eagle Talon TSi AWD
    13.620 @ 108.460 · 1G DSM
    Loading...
  11. DSM B

    DSM B Probationary Member

    20
    3
    Joined May 22, 2012
    Minneapolis, Minnesota
    Heys guys, I'm really liking this thread as I am having the exact same issue. I feel things are dialled in but then I have tip in, or free rev bog that i suspect is a rich bog. Jacob, are you speed density or MAF?

    I guess I have never reviewed someone else's log, can I add in their map and wideband as they are light gray when I view his log.
     
  12. Jacob_Barnes520GST

    Jacob_Barnes520GST Proven Member

    100
    8
    Joined Feb 21, 2018
    Tucson, Arizona
    I am running a stock 2g maf, not on speed density. I will post up another log when I'm at work. I know it's a lean stumble-because the wideband will read anywhere from 16.8-22.0 when I press on the gas initially. Once it starts to move it corrects back to ~14.7.
     

    Street Build 584  8

    1995 Mitsubishi Eclipse GST
    fwd · automatic · 2G DSM
    Loading...
  13. MattHDSM

    MattHDSM Probationary Member

    28
    17
    Joined Oct 20, 2018
    Ottawa, ON, Canada
    A stumble on tip-in does sound like there might be an issue in the tune, but the lean reading I would argue is always going to happen to some degree. I'm certain there are ways to minimize tip-in lean and tip-out rich, but I feel like it should be stated that it can't be entirely eliminated when using a cable driven throttle body. When you go from closed to open, you have atmospheric pressure rushing into a vacuum (The velocity of air at atmospheric pressure rushing into a vacuum can reach nearly supersonic speeds depending on the volume of vacuum being displaced) which will drastically increase the volume of oxygen entering the combustion chamber. I don't think our ECUs run fast enough to react to any sensors and adjust before air and fuel have entered the combustion chamber.

    Engineering Explained posted a video where he talks about rev hang, but in the video he explains the problems with mechanical throttle bodies regarding tip-in lean and tip-out rich, also how they have a non-linear torque vs throttle position. Pretty interesting in my opinion.
     

    Street Build 451  4

    1997 Eagle Talon TSi AWD
    16.870 @ 82.17 · 2G DSM
    Loading...
  14. TK's9d2TSi

    TK's9d2TSi Supporting Member

    3,607
    1,249
    Joined Sep 11, 2017
    Cincinnati, Ohio
    Zero out your fuel slider and get your MAF comp somewhat smooth. This should fix your issue. Links demo video goes over this. It desperately needs a tune.
     

    405  3

    2000 Jeep Cherokee Sport - Classic
    awd · automatic · Misc Vehicles

    459  4

    93 Civic 4 Door -sold-
    fwd · manual · Misc Vehicles

    Street Build 3K  6

    1992 Eagle Talon TSi AWD
    12.2 @ 120 · 1G DSM
    Loading...
    1990TSIAWDTALON likes this.
  15. 1990TSIAWDTALON

    1990TSIAWDTALON Moderator

    6,470
    2,762
    Joined Nov 14, 2013
    Independence, Kansas
    Saw the sliders myself but since they started at 2k, I didn't mention them. Good eye tho Tony!!!
     

    Street Build 5K  29

    1992 Eagle Talon TSi AWD
    14.74 @ 117.04 · 1G DSM

    1K  14

    1990 Mitsubishi Eclipse GSX
    awd · manual · 1G DSM

    793  18

    1967 Chevrolet Camaro RS
    rwd · automatic · Misc Vehicles

    Street Build 1K  7

    1998 Eagle Talon TSi
    fwd · manual · 2G DSM

    Street Build 6K  14  25

    1990 Eagle Talon TSi AWD
    13.620 @ 108.460 · 1G DSM
    Loading...
    TK's9d2TSi likes this.
  16. Jacob_Barnes520GST

    Jacob_Barnes520GST Proven Member

    100
    8
    Joined Feb 21, 2018
    Tucson, Arizona
    I appreciate the help everyone. I made the adjustments and will post a log when I get a chance
     

    Street Build 584  8

    1995 Mitsubishi Eclipse GST
    fwd · automatic · 2G DSM
    Loading...

Share This Page

Support Vendors who Support the DSM Community
ECM Tuning ExtremePSI Feal Suspension Fuel Injector Clinic Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications OHM Racing RixRacing RockAuto SouthBay Fuel Injectors STM Tuned Track Decals Track Sculptures VR Speed Factory