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Bobcat 863 duetz 1011f surging

Rocko ยท 2012-09-20 22:19

Bobcat 863 surging at all speeds. Have change fuel filter and look at all fuel lines for air leaks but have found nothing. Start fine then surges for a minute and levels out. When start use the machine it run smooth until load is put on it then surge and regain power. It is worse at mid throttle position than any other position. Stump need some help thanks.

Replies13
  1. #1willie592012-09-20 22:48

    When it surges under load (engine stalls), check to see if primer bulb is collapsed, if it is, you have something blocking the pick up inside fuel tank. If it's not collapsed, if your fuel lift pump looks similar to pic below, remove the screw in center of cap on lift pump, remove that cap, many pumps of this style have a strainer screen inside them that gets clogged.

  2. #2Rocko2012-09-20 22:58

    It never stall just surges the rpms lower probably a few hundred rpms but I will look at the screen tomorrow I have not check that and did not know it was there thanks. Also every time I have tried pumping the primer bulb it's has been stiff and hard to pump so it should be primed up I did take the fuel line off the filter output to make sure lift pump was pumping and it seem good. Primer bulb is stiff even when surging tried that too.

  3. #3willie592012-09-20 23:21

    If you have a stiff primer bulb, things are normal there, it should be stiff to the pumping by hand. The surging (or engine stall) is indicative of a fuel delivery problem. On other diesel engines, one would have to include injection pump as a suspect. But on the BF1011F, each cylinder has its own injection pump driven by a cam shaft. Granted, a problem with the fuel control rack for these pumps could cause problems, but I highly suspect this is not the case. It just sounds like you have a fuel delivery problem the way the engine is "stalling out", then when you "back off" controls it recovers.

  4. #4crewchief8882012-09-21 19:57

    without hearing the surging it's hard to tell. if the fuel delivery system is in good shape, the problem may be a weak or broken fuel rack return spring a "sticky" fuel pump worn governor :drinkup

  5. #5siduramaxde2012-09-21 21:14

    could possibly be a bad connection/broken wire to your fuel solenoid

  6. #6Bobcatdan2012-09-23 20:31

    Check the engine oil level. If it is over full, the transfer pump very well could be leaking fuel into the engine, starving the engine. I see two or three a year that do that.

  7. #7barklee2012-09-23 21:47

    This engine has fabric wrapped metric fuel rail lines. Do any of the lines look wet or are there any minor leaks? Also this rail uses plastic T connections, sometimes these split very slightly. If this isnt the case than inside the fuel pump there is a screen that can clog. Try to clean this and blow out the fuel lines with air.

  8. #8amwilkin2013-05-18 11:09

    Fuel restriction leaving tank into fuel line. Been there many times.

  9. #9Mr.Ron_tx2013-05-18 13:52

    Hey Y'all.. I'm new here , so bear with Me and My weird questions I have a 2001 Bobcat 863G with the Duetz BF41011F engine. I have had problems with the fuel shut sylenoid about three times. I have found that when it wont start and I heard the lifeless turning of the engine...it's acting up again. I have found that sometimes I can remove ,bump it with jumper wires from the battery...it clicks..I reinstall it and it works for a year or so. Today ,Im not so lucky. I have installed two..one new and one used....both clicked but the engine won't fire up.... I have a sinking feeling that the fuel shut off lever inside the housing is broken or wornout... Any ideas ???? Thanks.

  10. #10amwilkin2013-05-18 14:10

    My 863 does the same thing, only more often. I believe it is caused by a faulty seat bar safety switch. I just hot wire and run. Alvi

  11. #11Mr.Ron_tx2013-05-18 14:26

    Hmmm Thanks for the fast reply.... I am wondering if the seat bar switch hasn't already been "worked"on...yet I cannot operate without the bar down..but it will fire up with the bar up....Hmm....gonna go poke around some more... Thanks.

  12. #12Mr.Ron_tx2013-05-19 09:52

    I looked last night and found the bar switch....it has three blue wires with all three the same size...how did You bypass it?? Thanks.

  13. #13amwilkin2013-05-19 12:45

    Great question, I would like to know myself. I run a hot wire from the battery to the wire that goes to the fuel solenoid. Risky but gets the job done. O would likely shut it down. Good luck alvi