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Thread: cammed 4.3l popping at idle

  1. #1
    Potential Tuner
    Join Date
    Sep 2018
    Posts
    3

    cammed 4.3l popping at idle

    I have 2003 blazer with a 4.3l that I have done some upgrade on. I know this is a v8 forum, but it is gen3 so I am hoping there is some input I can get here. I have added a cam (Comp Cams 56-450-8), valve springs, marine intake manifold, injectors (bosch 0280158165), cat delete, and straight exhaust. I have roughed in the maf and ve table tunes along with updating the injector data. I have a problem with excessive popping coming from the exhaust when at idle or deceleration, but not as frequently. I tried initially swapping the injectors thinking they were the problem, but that didn?t fix it. I found a hole in the y-pipe upstream of the passenger side O2 sensor and fixed that, but same thing. I have attached my current tune and a log file. I am unsure if there is a tune problem or a mechanical issue at this point. Any feedback from someone more experienced with tuning would be greatly appreciated.

    200927-24lb-inj.hpl

    200927-24lb-inj.hpt

  2. #2
    Advanced Tuner
    Join Date
    Jun 2008
    Posts
    539
    Quote Originally Posted by knightriderjoe View Post
    I have 2003 blazer with a 4.3l that I have done some upgrade on. I know this is a v8 forum, but it is gen3 so I am hoping there is some input I can get here. I have added a cam (Comp Cams 56-450-8), valve springs, marine intake manifold, injectors (bosch 0280158165), cat delete, and straight exhaust. I have roughed in the maf and ve table tunes along with updating the injector data. I have a problem with excessive popping coming from the exhaust when at idle or deceleration, but not as frequently. I tried initially swapping the injectors thinking they were the problem, but that didn?t fix it. I found a hole in the y-pipe upstream of the passenger side O2 sensor and fixed that, but same thing. I have attached my current tune and a log file. I am unsure if there is a tune problem or a mechanical issue at this point. Any feedback from someone more experienced with tuning would be greatly appreciated.

    200927-24lb-inj.hpl

    200927-24lb-inj.hpt
    I didn't look at the attachments. Is the distributor good, no slop. Especially the cap. I have a stock 2003 4.3 and it eats caps like nothing. They crossfire internally. I'm sure it's all new and you know this but just remember I don't know.