D12a engine will not rev

Discussion in 'Volvo Forum' started by niaymi, Dec 2, 2015.

  1. Dec 2, 2015 #1
    niaymi

    niaymi Bobtail Member

    9
    0
    Oct 11, 2013
    0
    Hello everyone, hopefully someone can help. Again the local Volvo dealer cannot help me with my 1995 WG64 D12a-370. Truck has been great for the last couple of years and on Friday as I was driving along a major hi way the truck started to sputter and got sluggish. All filters and maintenance are up to date. Turns out that when I press the fuel pedal the truck will rev to 1650rpm with no way to control it otherwise, so its either on at 1650 or idling. At idle or 1650 the engine purrs like a kitten. Took it in to the shop and they changed the fuel filter to rule out bad gas, checked the turbo, CAC, changed the pedal reo-stat and checked the fuel pressure which was a little low at 54lbs. Again, I cannot find a wiring diagram for this truck, it is not even available through the Volvo dealership...anybody had a similar problem?

    Any advice would be most appreciated!!!

    Thanks.
     
    niaymi, Dec 2, 2015
    niaymi, Dec 2, 2015
    #1
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

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

  3. Dec 2, 2015 #2
    nasriza

    nasriza Road Train Member

    2,407
    2,077
    Feb 1, 2013
    Chicago, IL
    0
    did they check the pedal itself if it is making any issues i know i have had good throttle position sensors on bad pedals and they make a lot of headaches
     
    nasriza, Dec 2, 2015
    nasriza, Dec 2, 2015
    #2
  4. Dec 2, 2015 #3
    nasriza

    nasriza Road Train Member

    2,407
    2,077
    Feb 1, 2013
    Chicago, IL
    0
    and if they can't find wiring diagram they don't know what the rheostat is supposed to put out anyway so the best way would be to call dealer and see if possible to get throttle assy assuming that it is cost effective
     
    nasriza, Dec 2, 2015
    nasriza, Dec 2, 2015
    #3
  5. Dec 6, 2015 #4
    Pablo-UA

    Pablo-UA Road Train Member

    7,604
    1,642
    Oct 11, 2010
    Borispol, Ukraine
    0
    Pull fault codes, sounds like bad pump ore bad tps
     
    Pablo-UA, Dec 6, 2015
    Pablo-UA, Dec 6, 2015
    #4
  7. Dec 11, 2015 #5
    benrab

    benrab Medium Load Member

    326
    238
    Apr 5, 2015
    Quebec ,Canada
    0
    If i understand correctly the engine run idle OK but when you push the trottle pedal the engine RPM increase up to 1650 Rpm without any control ?
    IF so,it look like the engine is running on Limp Home Mode .
    When you turn the engine Off is it stopping right away or there is a 10 second delay before the engine stop ?
    Ben
     
    benrab, Dec 11, 2015
    benrab, Dec 11, 2015
    #5
  8. Dec 12, 2015 #6
    Pablo-UA

    Pablo-UA Road Train Member

    7,604
    1,642
    Oct 11, 2010
    Borispol, Ukraine
    0
    and to be sure u need old Volvo adapter........ RS232 to Datalink............
     
    Pablo-UA, Dec 12, 2015
    Pablo-UA, Dec 12, 2015
    #6
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

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