Results 1 to 5 of 5

Thread: 4.3L S10 Blazer 5 speed wont rev past 4.5K

  1. #1
    Tuner in Training
    Join Date
    Dec 2015
    Location
    Greensboro, NC
    Posts
    19

    4.3L S10 Blazer 5 speed wont rev past 4.5K

    Hi Everyone,

    I have a 98 4.3L w/Manual transmission that won't rev past 4.5k. Looks like the injectors are being shut off, it switches loop, O2 go lean. Seams complete intentional. Any ideas?

    I have the rev limit set to 6K. (Trans mode shows D1, Clutch switch is okay) The engine is new and completely built (Forge internals and bla bla bla). This one has me stumped...

    Thanks!

    //Karl

  2. #2
    Potential Tuner
    Join Date
    Jun 2018
    Posts
    4
    You have the Rev limiter set up in your DEFCO?

  3. #3
    Tuner in Training
    Join Date
    Dec 2015
    Location
    Greensboro, NC
    Posts
    19
    yes, set it to 6K then 10K. Acts like Park/neutral rev limit. I also noticed that the DEFCO was still activating on decel, even though I've set the parameters beyond normal limits??? Crap ECU?


    (Just a FYI, I deal with API's and such in my day to day role, working for a vehicle manufacture. Not my first rodeo when it comes to parameters and signals)

  4. #4
    Tuner camaroguy28's Avatar
    Join Date
    Jul 2014
    Location
    Salem Virginia
    Posts
    67
    long shot, but have you checked fuel pressure as you are driving it up to that rpm? Reason that I ask is that my Camaro was going to 4500 rpms and it seemed like it was hitting a rev limiter and it was the fuel filter.

  5. #5
    Tuner in Training
    Join Date
    Dec 2015
    Location
    Greensboro, NC
    Posts
    19
    Thanks for your input, I need to add a port to check the pressure. (running the marine intake with external injectors and LS fuel filter (return-less system). I was thinking that it would bog more or I would see the it O2 decay voltage, but I suppose its worth checking.