Page 1 of 2 1 2 LastLast
Results 1 to 10 of 14

Thread: MEP 804b MPU source?

  1. #1
    Private
    Join Date
    May 2006
    Location
    Pelham,MA
    Posts
    23
    Thanks
    5
    Thanked 2 Times in 2 Posts

    Default MEP 804b MPU source?

    Hi,

    Does anyone know of a good source for an mpu for the MEP804b? New or takeoff is ok.

    Thanks

  2. #2
    Sergeant Major
    Join Date
    Dec 2008
    Location
    Near Apex/NC
    Posts
    163
    Thanks
    11
    Thanked 114 Times in 61 Posts

    Default

    If you mean the magnetic pickup, I bought mine from ebay. Search MSP6729 3/8”x24 around $20.

    Robert

  3. #3
    3 Star General
    Join Date
    Mar 2013
    Location
    Oregon
    Posts
    962
    Thanks
    633
    Thanked 1,002 Times in 533 Posts

    Default

    You should also post a free ad in the SS "Parts Wanted" Classifieds section unless you have already located one.
    GEN #1 House Gen PU-751/M: 1986 MEP-002a/M116A2 w/Aux Tank & OEM cover
    GEN #2 Spare Gen PU-751/M: 1991 MEP-002a/M116A2 w/Aux Tank & OEM cover
    GEN #3 Shop/Barn Gen NF-2 Enclosure: 19XX MEP-002a w/Aux Tank
    GEN #4 Spare Gen PU-751/M: 1991 MEP-002a/M116A2 (a work in process)

    * Disclaimer - My comments on this forum are based on my opinion and my experiences only. It is your responsibility to verify any information before using or to hire a professional.

  4. The Following User Says Thank You to Chainbreaker For This Useful Post:

    ehinlein (10-15-2019)

  5. #4
    Private
    Join Date
    May 2006
    Location
    Pelham,MA
    Posts
    23
    Thanks
    5
    Thanked 2 Times in 2 Posts

    Default

    Thanks for the quick replies! Just ordered but will definitely use the parts wanted section next time.

  6. #5
    4 Star General Guyfang's Avatar
    Join Date
    Dec 2015
    Location
    Burgkunstadt, Germany
    Posts
    6,269
    Thanks
    12,105
    Thanked 5,599 Times in 2,695 Posts

    Default

    Member 155mm bought his from a truck repair shop, i I remember right. Send him a PM and ask.

    Oh, whats wrong with yours?

  7. #6
    Chief and Indian 155mm's Avatar
    Join Date
    Oct 2011
    Location
    Guymon, OK
    Posts
    876
    Thanks
    365
    Thanked 851 Times in 429 Posts

    Default

    Correct, the small mpu on 804 is the speed sensor on the tranny on an 03 379 pete, the large is on an 03 w900 kenworth tranny
    "Artillery Brings Dignity to What Would Otherwise Be Just A Vulgar Brawl"

    "Happiness Is A Belt-Fed Weapon"

  8. The Following 2 Users Say Thank You to 155mm For This Useful Post:

    DieselAddict (10-17-2019), Guyfang (10-16-2019)

  9. #7
    Private
    Join Date
    May 2006
    Location
    Pelham,MA
    Posts
    23
    Thanks
    5
    Thanked 2 Times in 2 Posts

    Default

    Hello Guyfang,

    I didn't respond right away because I wanted to see if the speed pickup was the issue. It wasn't. The story. Nice clean 804b. Had for 18 months. From GP. Has always started and run fine. When I got it the fuel intake pipe in tank was bent upwards so required a fullish tank to run. Could be a hint that something was wrong and someone messed with it. Went to start it recently and it cranked fine but no start, no smoke. Thought maybe fuel. Checked at bleed and filters. Fuel good. Thought maybe pickup as this seems to be an issue. I swear I gently ran it in to stop and then backed 3/4 but after that upon crank, chewed it up. Live and learn. Anyway replaced that and get 2.8VAC on crank now. Only odd thing is that a couple of weeks prior to the no start condition I was moving it (no rear leg) and tipped it so it flipped on rear end, pintle to the sky for a short time (minute). Hadn't tried it since the tip. This was the first time. It was a gentle tip onto soft ground. Can't see this as cause but who knows. Any thoughts? I know. I know. time to break out the TMs.

  10. #8
    Sergeant Major
    Join Date
    Dec 2008
    Location
    Near Apex/NC
    Posts
    163
    Thanks
    11
    Thanked 114 Times in 61 Posts

    Default

    On my two 804ís if no smoke during crank, so far it has almost always been the MPU. On the A model, it has no fuel pump and it would lose the prime from time to time. Replaced the manual fuel pump doohickey and that part has been fine since, now the water pump is making bad noises with only around 150 hours total.

    On the B, no problems in more than 500 hours of running and it seems more robust than the A, especially when running a FDECU-5 (5 ton heat pump). Since the B has fuel pumps, let it run for around 5 minutes and maybe crack some lines to see if it is moving fuel and bleed it. You should hear the return dribbling into the tank.

    Yes, the TMs have some trouble shooting guides although the one about crank no start should begin with checking and verifying the MPU instead of near the end of the guide.

    Robert
    Last edited by robertsears1; 10-18-2019 at 16:37.

  11. The Following User Says Thank You to robertsears1 For This Useful Post:

    Guyfang (10-19-2019)

  12. #9
    Chief and Indian 155mm's Avatar
    Join Date
    Oct 2011
    Location
    Guymon, OK
    Posts
    876
    Thanks
    365
    Thanked 851 Times in 429 Posts

    Default

    You can operate injection pump by hand, for troubleshooting. Takes 2 soldiers unless you have really long arms. My guess is mpu same as robert. Unless something got knocked loose with the tip over. Might check all relays behind control panel
    "Artillery Brings Dignity to What Would Otherwise Be Just A Vulgar Brawl"

    "Happiness Is A Belt-Fed Weapon"

  13. The Following User Says Thank You to 155mm For This Useful Post:

    Guyfang (10-19-2019)

  14. #10
    4 Star General Guyfang's Avatar
    Join Date
    Dec 2015
    Location
    Burgkunstadt, Germany
    Posts
    6,269
    Thanks
    12,105
    Thanked 5,599 Times in 2,695 Posts

    Default

    Quote Originally Posted by ehinlein View Post
    Hello Guyfang,

    I didn't respond right away because I wanted to see if the speed pickup was the issue. It wasn't. The story. Nice clean 804b. Had for 18 months. From GP. Has always started and run fine. When I got it the fuel intake pipe in tank was bent upwards so required a fullish tank to run. Could be a hint that something was wrong and someone messed with it. Went to start it recently and it cranked fine but no start, no smoke. Thought maybe fuel. Checked at bleed and filters. Fuel good. Thought maybe pickup as this seems to be an issue. I swear I gently ran it in to stop and then backed 3/4 but after that upon crank, chewed it up. Live and learn. Anyway replaced that and get 2.8VAC (where are you mesuring this? At the MPU, or at the A5?) on crank now. Only odd thing is that a couple of weeks prior to the no start condition I was moving it (no rear leg) and tipped it so it flipped on rear end, pintle to the sky for a short time (minute). Hadn't tried it since the tip. This was the first time. It was a gentle tip onto soft ground. Can't see this as cause but who knows. (Like 155MM said, check the relays.) Any thoughts? I know. I know. time to break out the TMs.
    1. Charge your battery's. This set, like most TQG's work best when the batteries are in tip top condition.
    2. Have someone try and start the set. You make the following tests.
    3. See if you are getting 2.8 VDC at the A5 terminals 16 & 27.
    4. Go to the A6 and see if you have 7.8 ohms across the coil, and 24 volts at the P10.

Page 1 of 2 1 2 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •