12.7 Detroit backfires and throws fireballs

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by Flipp, Apr 11, 2020.

  1. Shawn2130

    Shawn2130 Heavy Load Member

    870
    1,806
    Sep 20, 2015
    Ontario
    0
    Sound like an injector going out of time or sticking.
     
    Dino soar and Rideandrepair Thank this.
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

  3. stillwurkin

    stillwurkin Road Train Member

    1,756
    2,855
    Dec 2, 2017
    0
    Just grabbing at straws. Could the fuel pedal sensor make it act up? I know they can do other odd things. Not a very expensive item to try.
     
    Rideandrepair Thanks this.
  4. Rideandrepair

    Rideandrepair Road Train Member

    16,472
    53,810
    Aug 8, 2015
    0
    I can only imagine the fire is from Unburnt fuel maybe, lining the exhaust, till it ignites. The fire does look cool. Lol.
     
    Shawn2130 Thanks this.
  5. Shawn2130

    Shawn2130 Heavy Load Member

    870
    1,806
    Sep 20, 2015
    Ontario
    0
    It does look like those sled pulling trucks and tractors.

    They always have flames popping while revving up, then become solid orange flame before becoming pure black smoke.
     
    Rideandrepair Thanks this.
  6. Flipp

    Flipp Bobtail Member

    13
    15
    Apr 16, 2019
    0
    Glad you guys think my problem looks cool haha.

    I would think if there was a bunch of fuel not burning the thing would roll coal, it really doesn't smoke at all, at full throttle it smokes a little but thats it
     
    Rideandrepair and Shawn2130 Thank this.
  7. Shawn2130

    Shawn2130 Heavy Load Member

    870
    1,806
    Sep 20, 2015
    Ontario
    0
    Flipp: if the injector doesn’t fire at the right time, it will send a flame through the exhaust and out the pipe.

    Or the fuel started burning while on its way out if it didn’t burn in the combustion chamber and ignited from hot surfaces inside.
     
    Rideandrepair Thanks this.
  8. Flipp

    Flipp Bobtail Member

    13
    15
    Apr 16, 2019
    0
    What would cause an issue like that? If it was a bad injector or somthing it should have went away when I replaced them. If it was the cam timing, first of all I would think it wouldn't be so intermittent, it would be a constant thing wouldn't it? The one thing I have never looked at is the ECU. I have had multiple people plug into it and tell me everything looks good, and with the price to replace it I haven't been able to justify it without some kind of proof that it's likely the cause. I understand the mechanical side of things but the electrical stuff is not for me.
     
    Rideandrepair and Shawn2130 Thank this.
  9. terryt

    terryt Heavy Load Member

    736
    775
    Apr 27, 2009
    0
    mine was doing the same thing turned out to be a stuck jake brake solenoid replaced the solenoids no more backfire
     
    Oxbow and Rideandrepair Thank this.
  10. Flipp

    Flipp Bobtail Member

    13
    15
    Apr 16, 2019
    0
    Already rebuilt the Jake's and replaced the solenoids. No luck for me
     
    Oxbow and Rideandrepair Thank this.
  11. Shawn2130

    Shawn2130 Heavy Load Member

    870
    1,806
    Sep 20, 2015
    Ontario
    0
    Flipp: when it comes to electronics, they’re either constantly causing the issues or intermittent or very rare.

    Injectors likely are fine, but still controlled electronically.

    It could easily be a lazy sensor which shows it’s still working but act up sometimes.

    ECU can work good, then have a sneeze, then work again.

    I myself was trying for a time to trace down an issue with the ACERT C15 I used to drive. Most times works great, then at odd time’s, falls flat on its face.
     
    Rideandrepair Thanks this.
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.