Engine Dies While shifting please help!

Discussion in 'Mack Forum' started by MACKDADDY, May 11, 2012.

  1. MACKDADDY

    MACKDADDY Bobtail Member

    5
    1
    May 11, 2012
    Munising, MI
    0
    I have a 1993 Mack 400. The problem i am having is when i am pulling out from a stop and i start shifting through gears the engine dies just like i shut the key off, or if i am downshifting the engine dies the same way, but by the time i realize what is happening i release the clutch and the engine is running again. Im thinking it may be something in the jake or some kind of fuel shut off or an ignition problem. Im in a real bind can somebody help!!!!!!
     
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

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

  3. bender

    bender Road Train Member

    2,105
    1,347
    Jul 20, 2010
    Don't Kid Yourself
    0
    The Jake switch is built into the pump and is adjustable. Is your fuel shutoff manual cable operated or electric solenoid? If it only happens when you let off the throttle then it most probably is the Jake. Have you turned the Jakes off and tried it. It could also be sucking air into the fuel system. Does idle and power seem normal?
     
  4. MACKDADDY

    MACKDADDY Bobtail Member

    5
    1
    May 11, 2012
    Munising, MI
    0
    As far as i know its an electronic fuel shut off. Two nights ago the thing quit 3 times with the jake on. yesterday i run it with the jake off and had no problems, but its so intermitten that i cant really tell if it works i went the whole summer last year never having a problem, then come fall it started quitting again. I was also wondering if there is some kind of neutral saftey switch on the tranny or something of that nature. Anyway thanks for the tip i will run with the jake off for awhile and see what happens. If you have any more ideas i will gladly try them. Thanks
     
  5. bender

    bender Road Train Member

    2,105
    1,347
    Jul 20, 2010
    Don't Kid Yourself
    0
    If the engine shuts off with the key then it's electric solenoid. Mack was big on manual shutdown with a pull knob in the dash. I've had to adjust the Jake setting on those pumps in the past, not a big deal if that's all it is. If the truck had a safety switch it would be on the clutch pedal and prevent cranking only until the pedal was depressed to activate the switch.
     
  6. MACKDADDY

    MACKDADDY Bobtail Member

    5
    1
    May 11, 2012
    Munising, MI
    0
    Ok well thank you for the help, one more question, how do i adjust the jake and if it needed to be replaced is it a big job?
     
  7. bender

    bender Road Train Member

    2,105
    1,347
    Jul 20, 2010
    Don't Kid Yourself
    0
    The Jake adjustment screw is on top of the injection pump. Adjust the screw to desired sensitivity or Jake response when you let off the throttle. Replacing Jakes would get very involved but I doubt you'll find that necessary.
     
    MACKDADDY Thanks this.
  8. MACKDADDY

    MACKDADDY Bobtail Member

    5
    1
    May 11, 2012
    Munising, MI
    0
    Thanks a bunch really helped a lot
     
    bender Thanks this.
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

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