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Thread: 02 trailblazer 4.2. Learning parameters for boost all trial n error

  1. #1
    Tuner in Training
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    Jul 2019
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    11

    02 trailblazer 4.2. Learning parameters for boost all trial n error

    New to tuning any efi vehichle let alone gm ....bought a 02 trailblazer ls 4.2 with 220k on it jan 1 19 and me being raised in this environment of being mechanically enclined at everything put in my path i new n could feel vehichle wasnt operating at full potentional so i started replacing #ALL SENSORS...and it started getting shit%y gas mileage so wen i would be hauling 5 or 6klbs of timber it was killin my pocket so i ordered a jet dst 14005 first read came bck as 11 chevy silverado 1500 ecm n tcm. Since then ive crashed compiter from to mny constant flashing. So i ordered tune from pmcof nc core program n kept my so called brickrd pcm wen i rd the pmc comp with my jet dst it came bck as same and i couldnt see the changes physicalky with dst do to no info support so i upgraded to hp tuners mpvi2 pro feature with prolink and have the aem wide eugo controller kit... I did first read on my tn with hp tuners n idk how but it came back as a 2010 comaro ss tune read...so i purchased ceedits for vehichle n wat do u kno the 8 thst come with hp tuners idk werethey are or hot to use them i have bought 9 universal credits n have my original bricked pcm vehichle loaded with 5 credits n my pcmofnc comp got vvrhichle specific universal credits of 2 each so hoe do i use the vcm to rewrite these to my vehucle n i got a good tune i like but wot and tcc full lock up is given me trouble im learning for boost that is being built. Due out jsn 2020 banging strait6BOOSTED TB so if anyone would lile to be part the bandwagon its greatly appreciared 1 hand washes the other

  2. #2
    Advanced Tuner
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    May 2006
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    Seattle, WA
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    Welcome, your post is a bit difficult to read but think I got the jist of is. I own an 02 I6 TB and have tuned over a dozen 02-05 P10 TrailBlazers over the years, not as many as PCMofNC, but I've done enough to know the limitations of the PCM pretty well.

    You're going to have massive issues trying to tune it for boost. It's a Speed Density/alpha-N style PCM and there are no enhanced OS' that will allow you to read boost in the PCM. As soon as you get over 105 kPa i.e. naturally aspirated, the PCM will throw a handful of range codes and go into REP mode. You can disable that, but you're stuck with the last row of the VE and spark tables as the singular value for when in boost (not ideal). So you'll need to figure out how to control the fueling when the PCM can't, either piggyback, standalone, or similar. It also uses Load for one of the axis of the VE tables which is mapped to throttle position, not MAP.

    You could try to scale the PCM and half the resolution of all spark/VE tables to get it close (look at the thread called- hacking a 2 bar tune- think there's a thread on here for some guys who did it with a 4cyl PCM which uses a similar engine control strategy). This may work, but you'll be using half the size of the tables so idle and part-throttle driving may not be great.

    I've planned to boost mine for years, just never got around to it. What I have seen other have success with is to swap the P10 for an 04-06 P12 PCM from a TB/Colorado. With that PCM, you can use a MAF and get the fueling dialed in. You still have the issue with running out of spark (and VE) tables in the PCM when in boost, but you can at least tune the MAF curve to keep the fueling correct.
    ~Erik~
    2013 Sonic RS - manual, CGM, 6M, sunroof, mods in process
    2008 TrailBlazer 3SS AWD LS2, loaded, dropped, modded, SE22 Performance tuned. And then some...
    2002 TrailBlazer LT 4WD 4.2L I6, lifted, tires, exhaust, SE22 Performance tuned

  3. #3
    Tuner in Training
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    Jul 2019
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    Im intriged by the knowledge u have with these vehicles id like to ask u further more questions on ur input that im having trouble grasping around my number is 7279535243...my name is larry walker i also own a tree business if ur in the state of fla All The way Up Tree Services LLC...motors in the shop now btw so i have little crunch time thanks for ur time if your interested sincerly

  4. #4
    Advanced Tuner
    Join Date
    May 2006
    Location
    Seattle, WA
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    538
    Shoot me a PM and we can discuss further over the phone.
    ~Erik~
    2013 Sonic RS - manual, CGM, 6M, sunroof, mods in process
    2008 TrailBlazer 3SS AWD LS2, loaded, dropped, modded, SE22 Performance tuned. And then some...
    2002 TrailBlazer LT 4WD 4.2L I6, lifted, tires, exhaust, SE22 Performance tuned

  5. #5
    Tuner in Training
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    Jul 2019
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    11
    i cant fig out how to pm u