Results 1 to 4 of 4

Thread: P0299 tune related

  1. #1
    Tuner in Training
    Join Date
    Apr 2013
    Posts
    12

    P0299 tune related

    Ill will make this short and hopefully easy to understand so someone can help me out.

    The car runs ok on stock tune but in my attempt to up the boost with a tune creates this P0299 (Underboost). So its tune related.. Im fairly sure. Once the car gets the code is drops boost to 5psi and wont run anymore boost until code is cleared. Then it runs fine for a little.

    Whats in the tune?

    Slightly calibrated maf
    GMPP DAL table
    Low WDGC (wanted to start very low boost)

    Second issue is that the car isn't achieving targeted lambda's. Sometimes it doesn't have this issue.....

    Data Log and Tune below:
    Attached Files Attached Files

  2. #2
    Senior Tuner cobaltssoverbooster's Avatar
    Join Date
    Dec 2008
    Location
    Nevada
    Posts
    4,452
    first your code issues:
    1) engine diag section there are a few adjustments still needed.
    A) over and under boost Enable rpm- set to max allowable value
    B) Boost sensor range high p0236 copy and paste to map sensor p0106 range high

    2) tune corrections to help with boost control.
    A) trq man turbocharger- duty cycle corr- far right side lowest number at 255 dals should be 70% to start
    B) pressure rpm factor- raise to max
    C) pressure limit raise to max
    D) trq man engine- opti trq- raise right column to 100 from 3500 to max rpm. then smooth entire from 139% load to 200% load once or twice then correct the far right column as mentioned before. this will be a good start but fine tuning this helps. it will be hard to see the gains without a dyno to watch the trq curves
    E)trg man general- max trq- both value and table for max trq set to 100%. Under the max air load trq from 3500 to max set to 100 then hand smooth the previous cells into that.
    F)Load dampening- set disable

    all of that is trq management stuff that will cause throttle plate movement and boost limiting. if not corrected you may chase your tail trying to dial in boost forever.

    3) afr changes fuel control
    A) power enrich lambda chart- you dont need to add fuel in the 80% load column until about 5k rpm. if you happen to cruise into an 80% load cell which happens during hills and mountain cruise control operation you will trash your gas mileage. the cylinders at 80% load dont see a whole bunch of heat so you can leave them alone until the upper rpm limit then throw a little extra in for cooling effect if you wish. in the gmpp tune the 90 and 100% columns are the only 2 they adjust so they have factory proven those two to be best left alone for gas mileage already.
    B)finaly reset your maf curve back to stock and start over as you will run into fueling changes from these new tune updates.


    the reason you threw the code in the first place is because you lowered the wgdc to 50% at wot and probably boosted what about 8-10 psi which is 4-6 less than what gm stock (non gmpp) commands. if you have a full gmpp tune it commands about 18-20 so there you can imagine with a 8-10 psi drop and a threshold of 3 psi less than commanded to throw an underboost code its quite obvious why you throw the code consistently.

    if you still have code problems after the mentioned fixes then you will have to test sensors and circuits to guarantee proper operation. show us your next tune and scan when you get around to another test session.

    -csobb
    Last edited by cobaltssoverbooster; 08-30-2013 at 11:49 PM.
    2000 Ford Mustang - Top Sportsman

  3. #3
    Tuner in Training
    Join Date
    Apr 2013
    Posts
    12
    Cssob,

    I got a chance to make the changes you recommended and did a couple pulls. Car runs well now on this new tune. One thing I would really like your input on is the A/F from 1,900 - 2,500rpm. Something in the tune is preventing a smooth ramp in. I think the car hits this rpm/load a lot in everyday driving and is causing some KR and reducing drivability. My WGDC is preventing a better spool from the turbo so ignore the boost. Right now I am focused on the A/F hump.

    Side note:
    What specific changes are needed to compensate for horrible cali gas. I have read that turning down the hom low single table is the fix.. how many degrees do you think I should take it "down." I often get up to 2deg KR. Is the table forgiving? What x,y ranges need to be turned down?



    Thanks again,
    spmtn
    Attached Files Attached Files

  4. #4
    Senior Tuner cobaltssoverbooster's Avatar
    Join Date
    Dec 2008
    Location
    Nevada
    Posts
    4,452
    1900-2500 should be a power enrich of 1.0 which is stoich. no reason to alter values below 80% loads and 3,000 rpm.

    the cali gas is more something you have to play with. table is forgiving and all that happens is it either knocks more or it goes away.
    2000 Ford Mustang - Top Sportsman