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  1. #1

    Default diablo tuner, truck dies

    OK, a buddy of mine has an 07 4.8L 2wd silverado and installer a Diablo tuner to compensate for a larger tire siz and yet correct speedo readings. He switched back to a factory size tire and tried to pull the settings with his Diablo tuner unsuccessfully. I work at a dealer and told him we could try reprogram his ecm to the latest update and that should get him back to factory specs. He didn't tell me he only used his tuner to change tire size or I would have changed that with a tech 2. I figured he did some kind of engine tune or something. Well after reprogramming the ecm the truck ran great until he drove 20 feet and it died. Idles fine but once you drive drive 15 to 20 feet it just dies. No codes stored any modules. I performed ck. Shaft variation relearn and idle relearn after programming. Anyone have a clue what I should do? Truck ran great seems to idle a little lower now. Should I just try and adjust things with the Diablo?

  2. #2


    Which model do you have? I have the trinity and to role any changes off all I would do is select uninstall tuner... this resets the ecm and TCM back to before the initial install.

    You said you installed/updated the ecm? If you did this while the tuner is installed... I'm not certain but you may not be able to just uninstall the tuner now. I'd recommend calling their tech support.
    2009 Chevy Silverado 2500HDLT 6.0L w/ Towing Package, Dick Cepek GM8 Rims, Dick Cepek FC II 33X11.50R17,RKSport Ram-Air Hood(Functional), Lazer Lite Aluminum Tonneau Cover, Road Armor Stealth Bumper, PIAA Lighting, Diablo Trinity Tuner, Diablew Custom Tune, BullyDog Cold Air Intake, American Racing Headers w/highflow cats, Corsa Performance Sport Exhaust, Custom Striping, Black Bowties front and rear, Fuel Grille Inserts, Recon Headlights, Readylift Shocks, Readylift Upper Contol Arms, 2" Blocks in the Rear..

    Future Plans: HD Tie Rods, Under hood upgrades, Crower Camshaft and possibly electric fans.

  3. #3


    I'm not sure which model he has, he forgot to bring it lol. He said he tried to uninstall but was unable to do so.

  4. #4

    Join Date
    Sep 2010
    everett, massachusetts


    Quote Originally Posted by cory100fm View Post
    I'm not sure which model he has, he forgot to bring it lol. He said he tried to uninstall but was unable to do so.
    since the PCM is now programed and you have no codes check the fuel rail pressure. low idle no codes can be fuel pressures too low.

  5. #5


    I was planning on checking fuel pressure that day but a big storm was blowing in and I was on my bike that day, so I hauled ass outta there. Ill check it Monday.

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