Results 1 to 11 of 11

Thread: Any idea why I have tip-in hesitation? w/scan

  1. #1
    Tuner
    Join Date
    Dec 2012
    Location
    Atlanta
    Posts
    64

    Any idea why I have tip-in hesitation? w/scan

    Hey guys, my Silverado (in sig) has always had about a half-a-second hesitation whenever I hit the throttle harshly. I say hesitation, but actually it falls on it's face a little and then the rpm shoots up as it should.
    My afr's are pretty well dialed in across the board (olsd), and it doesn't just do it from idle, for example it can be humming along at 3,000 rpm and then you whack the throttle, and it falls asleep for a split second before it roars to life.

    Sorry, I don't have my wideband hooked up in this scan.
    Attached Files Attached Files
    Last edited by blkws6; 01-19-2014 at 08:52 PM.
    1999 Silverado, 383ci iron block forged stroker, 76mm turbo, 4l80e, A1000 etc
    737rwhp @16psi 926rwhp @25 psi
    Sold 2007 TBSS 408ci forged stroker, 76mm turbo, etc
    626rwhp @13psi
    Sold 1999 WS6 Trans Am 346ci, Procharger, Mahle pistons & rods, stage 5 RPM T56, Moser 12 bolt, Walbro, etc
    615rwhp @ 14psi

  2. #2
    Tuner
    Join Date
    Dec 2012
    Location
    Atlanta
    Posts
    64
    bump
    1999 Silverado, 383ci iron block forged stroker, 76mm turbo, 4l80e, A1000 etc
    737rwhp @16psi 926rwhp @25 psi
    Sold 2007 TBSS 408ci forged stroker, 76mm turbo, etc
    626rwhp @13psi
    Sold 1999 WS6 Trans Am 346ci, Procharger, Mahle pistons & rods, stage 5 RPM T56, Moser 12 bolt, Walbro, etc
    615rwhp @ 14psi

  3. #3
    Advanced Tuner
    Join Date
    Apr 2006
    Location
    western NY
    Posts
    339
    any time i ever had tip in hesitation i was to lean,but every vehicle has its quirks to figure out.
    2000 Firebird,2002 O.S.,LQ4 370,Borg Warner S475,truck mani.,Eagle crank,Callies Compstar Rods,Wiseco-11 4.030 pistons 9.4:1 comp.,LS3CNC heads,LS3 intake,NW92mm throttle body,ID1000 injectors,BTR trunion upgrade,LJMS STG3 cam,LS7 Lifters,ARP Studs-bolts,Frozen Boost A to W intercooler,JGS 60MM BOV,2 40mmJGS Wastegates,4L80E trans wth segment swap,CircleD 3400 single disk,MOSER 12 3.31gears ,BMR K-Mem.,2 Walboro 450 pumps,Returnstyle fuelsystem MAGNAFUEL regulator.
    LS1Tech sig KRAZY K 2000 TA

  4. #4
    Advanced Tuner 68Camaro's Avatar
    Join Date
    Mar 2011
    Location
    Van Buren, AR
    Posts
    326
    I noticed that not all of your torque management has been disabled. max torque is at 350 - max this table out. I don't know if this is your problem or not but I always max this table.

  5. #5
    Advanced Tuner 68Camaro's Avatar
    Join Date
    Mar 2011
    Location
    Van Buren, AR
    Posts
    326
    holy crap! I just noticed that your power enrichment and boost enrichment all are set to 1.00! this is basically no power enrichment! This thing has a turbo on it? these tables need set up. Throttle is right also - most of the time if you have poor tip in throttle response the ve table is lean in that area or you need to work with transient fueling.

  6. #6
    Tuner
    Join Date
    Dec 2012
    Location
    Atlanta
    Posts
    64
    Quote Originally Posted by 68Camaro View Post
    holy crap! I just noticed that your power enrichment and boost enrichment all are set to 1.00! this is basically no power enrichment! This thing has a turbo on it? these tables need set up. Throttle is right also - most of the time if you have poor tip in throttle response the ve table is lean in that area or you need to work with transient fueling.
    Yeah I know, I couldn't believe it the 1st time I saw that either. (I bought already built, tuned, broke-in,) The afr looks pretty good across the board (14.7 light throttle to 10.9 at high boost levels. I have contemplated fixing all of that, and doing it right, but other than that tip-in hesitation, it runs perfect. I've owned it for a year and a half and it can handle stop n go traffic and it runs in the 10's without any issues.
    So I guess I haven't had much motivation to fix the tune. I guess I'll mess with the transient fueling and tq mngmnt, and if that doesn't help, then i'll fix my VE, PE & BE.

    Thank you for the help
    1999 Silverado, 383ci iron block forged stroker, 76mm turbo, 4l80e, A1000 etc
    737rwhp @16psi 926rwhp @25 psi
    Sold 2007 TBSS 408ci forged stroker, 76mm turbo, etc
    626rwhp @13psi
    Sold 1999 WS6 Trans Am 346ci, Procharger, Mahle pistons & rods, stage 5 RPM T56, Moser 12 bolt, Walbro, etc
    615rwhp @ 14psi

  7. #7
    Even though the fueling is technically where it you want it at the end of the day. With the enrichment tables being 1.00 and wot being at 10.9 the ve table is probably butchered. So even though you're fueling is where you want it, the car isn't getting an accurate representation of the actual airflow going into the motor. I'd imagine that if you properly redid it it would drive a hell of a lot better, and probably make more power as well.

  8. #8
    Tuner
    Join Date
    Dec 2012
    Location
    Atlanta
    Posts
    64
    Thanks for the input gentlemen.

    Well last weekend I finally went through all of your suggestions, and surprisingly, nothing seemed to make the hesitation any worse or better.
    -I maxed out the tq management.
    -I basically started from ground zero with PE, BE, and adjusted VE appropriately for afrs to match commanded.
    -I also messed with transient fueling.

    I will say that I have never dealt with transient fueling before, so I don't know that I can write that one off just yet. I only messed with the "fuel boiling time..." and "wall to impact factor" tables. I tried increasing the entire tables in 10% increments and then decreasing, but nothing seemed to have an affect.
    Is there something in particular that you would suggest I should be doing with transient fueling?
    Attached Files Attached Files
    1999 Silverado, 383ci iron block forged stroker, 76mm turbo, 4l80e, A1000 etc
    737rwhp @16psi 926rwhp @25 psi
    Sold 2007 TBSS 408ci forged stroker, 76mm turbo, etc
    626rwhp @13psi
    Sold 1999 WS6 Trans Am 346ci, Procharger, Mahle pistons & rods, stage 5 RPM T56, Moser 12 bolt, Walbro, etc
    615rwhp @ 14psi

  9. #9
    Got a recent log with the hesitation?
    What injectors? and is the data correct for them?

  10. #10
    http://www.hptuners.com/forum/showth...A-how-to-guide

    that will help you a lot with understanding transient fueling.

  11. #11
    Tuner
    Join Date
    Dec 2012
    Location
    Atlanta
    Posts
    64
    Fixed it! Just needed to increase the Wall to impact Factor table a bit more. Yeah, that how-to was very informative (some of it was over my head lol).

    Thanks so much for the help guys!
    1999 Silverado, 383ci iron block forged stroker, 76mm turbo, 4l80e, A1000 etc
    737rwhp @16psi 926rwhp @25 psi
    Sold 2007 TBSS 408ci forged stroker, 76mm turbo, etc
    626rwhp @13psi
    Sold 1999 WS6 Trans Am 346ci, Procharger, Mahle pistons & rods, stage 5 RPM T56, Moser 12 bolt, Walbro, etc
    615rwhp @ 14psi