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Thread: losing my mind, need some help

  1. #1

    losing my mind, need some help

    The car is a 2002 Ws6 Trans am with
    6.0 iron block bored and stroked to 412 ci
    LT headers
    no cats
    full exhaust
    Custom Cam 240/240 609/609 112LSA
    Fi tech black 42lb injectors
    T5

    The car came in possesion of my brother and it obviouslly was thrown together, we have corrected much mechanically but the tune almost seems too far gone. I pulled what was off the car... the car has the following issues

    awful idle quality
    extreme rich idle- will make your eyes weep from the smell
    Commands a .90 eq at idle and cruise
    Doesnt seem to enable PE
    ive been unable to get a log worth anything due to that

    Tune attached
    OPTA.hptOPTA.hpt

    IM wondering if i should start from scratch or if this one could be saved, thanks for any help

  2. #2
    Tuner in Training
    Join Date
    Jan 2019
    Location
    Arkansas
    Posts
    19
    new to this myself but you can usually type in specifically what question you are wanting to ask in the search bar and it will pull up info. like 42lb injectors you can type that in and it will bring a thread up. I looked at it once I have 42lb injectors also and you have to change pulse width. way down to like .03 something. wish I could be more help, but learning.

  3. #3
    Tuning Addict 5FDP's Avatar
    Join Date
    May 2012
    Location
    Rogers, MN
    Posts
    13,533
    Your injector data shows 36ish/lb/hr where as you typed out 42lb/hr. Double check what pressure that was for. If it's 43.5psi and you are running 58psi which was factory, the data is even more out of whack.

    Verify the min injector pulse, offset vs volts and short pulse adder are correct for those injectors. If they came with no data, then that will be a lot tougher to dial in. You could maybe steal data from another vendors 42lb/hr injectors to try and help you.

    You open loop EQ ratio must be set to 1.00 for temps over 130-140 degrees. Otherwise if you read how the table functions it will always be richer if you are disabling closed loop. You can lean out the rest of the table some too if you like, it's doesn't have to be as rich as the factory tune is while it's warming up.

    If you have o2 sensor faults it can also not enter closed loop operating and aim for stoich.


    I would enable the short term fuel trims but disable the long term trims. You must get yourself a wideband o2 sensor so you can properly tune the airflow model. Probably 90% of the issue will correct themselves if the fueling is dialed in.

    Power enrichment is delayed to 5,500rpm, remove that limiter or reduce it. Then raise the MAP enable from 15kpa to something like 80-85kpa instead and use the pedal enable to control PE.

    This computer has the ability to use a speed density enhanced OS, you should apply that if this will be staying speed density. It will remove the secondary VE table and make tuning the primary VE much easier.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  4. #4
    I should of been more specific. Wideband is present. Just didnt dive too deep into it because the tune is so far off I didn't want to drive the car yet

  5. #5
    Did some digging and pulling lol. The fuel injectors are FIC redone factory ls1 to 42lbs. Flow matched to 1%. The fuel pump is the factory pump as well.

    It's a shame people touch these things and mess them up so bad.