3406 b sudden loss of power

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by tj379, Feb 3, 2022.

  1. tj379

    tj379 Light Load Member

    192
    165
    Nov 10, 2019
    ontario
    0
    hello , i have a 7fb 3406 b that i lost power on yesterday, truck has allways worked really well, can only get bout 15 -19 psi boost but takes a bit, it used did junp to 32-35 psi when u got into it, i changed fuel filters and blew out fuel lines,checked air filters,checked turbo,turbo is 2 year old cat and spins n looks like new inside with zero play,, did a wuick visual of charge boots, all looked ok and never changed anything , inpuuled afr line no oil in it, injection pump was totally rebuilt 2 years ago also , lookin for ideas, to me whdn i stab the throttle its not gettin euff fuel, it used smoke black when i stood on it not now, everything else is normal, egts, fuel n oil pressure, ideling, no missing , ? stumped
     
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

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

  3. Don379

    Don379 Heavy Load Member

    714
    1,285
    Jan 7, 2021
    0
    fuel psi at idle?
     
  4. tj379

    tj379 Light Load Member

    192
    165
    Nov 10, 2019
    ontario
    0
    that is what im not sure of, i do not have a gage on truck and weather is gettin bad here to rigg one up at the moment, what i can say is truck idels fines reves up dont sputter under liad and the transfer pump thats on it is a cat one and was replaced about 3 years ago
     
  5. Don379

    Don379 Heavy Load Member

    714
    1,285
    Jan 7, 2021
    0
    you in the middle of all that snow? rain out my way
     
    tj379 Thanks this.
  6. little cat 500

    little cat 500 Road Train Member

    1,949
    1,004
    Jan 17, 2010
    Abbottstown PA
    0
  7. MACK E-6

    MACK E-6 Moderator Staff Member

    45,827
    200,208
    Sep 19, 2005
    Baltimore, MD
    0
    @wore out would be our B model specialist. He’ll be along when he gets a chance.
     
    Last Call Thanks this.
  8. tj379

    tj379 Light Load Member

    192
    165
    Nov 10, 2019
    ontario
    0
    i pulled the afr line didn't see oil in it, it was repkaced when injection pump rebuilt not sure the life on em?
     
  9. wore out

    wore out Numbered Classic

    14,322
    173,740
    Jun 5, 2013
    CHASIN THE DEVIL'S HERD
    0
    When it’s sudden like that AFRC diaphragm is the usual culprit. I had one not long ago that broke the nail head off the small spool inside, spool was froze in the piston.
     
  10. tj379

    tj379 Light Load Member

    192
    165
    Nov 10, 2019
    ontario
    0
    thanks gonna have to pull it snd inspect thanks i will report back once completed
     
  11. tj379

    tj379 Light Load Member

    192
    165
    Nov 10, 2019
    ontario
    0
    wore out , what or how is the best way of testing the afrc , removal and visuslly inspect, air pressure leak sosn , vacuum lesk down test?
     
    Oxbow Thanks this.
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

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