2011 LS U5030C bogging down

npaden · Jun 30, 2016

I've had my new to me tractor for about 4 months now and have put a few hours on it and am pretty happy with it so far. The only real complaint that I have is that the foot throttle is too sensitive and I end up getting the thing jerking back and forth when I push on it with my foot in the middle gears. I think it is the way the pedal is designed but I'm just learning to use the hand throttle most of the time.

This past weekend I had my first issue with it though. I've just been using it for mowing, grading and loader work and things like that without putting much of a load on it, but this weekend I hooked up the disc and started plowing and putting a decent load on it.

At first it seemed like it had more than enough power to easily handle the 7' offset disc I was pulling but after a bit it seemed to bog down a bit and drop down to around 2K rpm at full throttle. I geared down a little but it seemed to still max out right around the 2K rpm mark even in lower gears. I ran it like that for a bit and then wondered if turning it off and back on would change anything. Sure enough I turned it off, let it sit a few seconds and started it back up and it ran like a champ. It would rev up to 2.5k rpm and was ready to pull like a champ. I started discing again and after a few minutes it bogged down a bit, then a bit more and it was back down to 2K rpm at full throttle again. It was still pulling okay and I just ran like that for a while and it dropped down to 1.8k rpm at full throttle and eventually down to 1.6k rpm at full throttle. Even if I put it in neutral and rev'd it up without a load at all it would only rev up to 2K rpm.

Again I turned it off, let it sit a bit and when I started it up it was back to normal again.... until it started the whole process over a few minutes later slowly bogging down more and more and then I would turn it off and back on and it would be back to normal again.

What would cause this? At first I thought it might be a governor problem, but now I'm hoping that it might be something as easy as the fuel filter needing changed.

Any thoughts?

Thanks, Nathan

holeycow · Jun 30, 2016

could even be a fuel venting issue. Air has to go in the tank as the fuel is going out....

the abrubt throttle could be sticky linkage needing some light lubing on the pivot points

farmer2009 · Jul 1, 2016

Start simple.

Change fuel filter.

Flush the fuel lines from tank to filter.

Sounds like debris in the tank and partially clogging fuel lines. Or fuel filter is starting to stop up. The key is if you let it set a few minutes it catches up.

Robojoe · Jul 6, 2016

My xr4145 done this tonight. Have you determined your issue yet? I was mowing and all of the sudden it dropped to 2k I switched off the pto and tried to raise rpm all while still moving in 3-1. Rpm wouldn't come up at all barely getting to 2k if I clutched the rpm would shoot up I had to pull throttle back to below 2.5k. I started the trip back to the house and down shifted to 2-1 before it would pull without rpm dropping. It still wouldn't rev to 2k however on the way home (1/2 mile) rpm slowly increased and I was able shift up to 3-4. Everything seemed fine when I got home. Any ideas?

npaden · Jul 16, 2016

Changed the fuel filter out and am still having the same issues. If I pump the manual bleed thing at the top of the filter it runs out great, but then it starts slowing up and drops down to that 1,800 rpm range and just stays there. When I pump the bleed it takes 3 or 4 pumps and then it gets pressurized and then it runs good, but after just 20 or 30 seconds I have to pump it again to keep it running at a high rpm. A mechanic friend thought it was a feed pump but talked with Alex at RCO tractors in Austin and he said it doesn't have a feed pump. I checked the fuel lines for kinks and there weren't any. I backflushed the line back into the tank and that didn't seem to do anything. Ran it with the fuel cap on and off and that didn't seem to make any difference. Pretty much at a loss here other than trying to take it to a diesel shop.

npaden · Aug 15, 2016

Finally got around to getting this fixed. Actually my neighbor who borrows my tractor fixed it for me. Somehow some air was getting into the system and that was what was causing the problem. He replaced the fuel hose and clamps and it works perfect again. Kind of a crazy deal, but very happy to have my tractor back running good again!

xmariner · Aug 15, 2016

npaden,

Glad to hear your problem was resolved. I too, am having a similar problem. Started (maybe) back in late April or May but it wasn't as severe as your tractor was exhibiting. I trailered the tractor(50 mi.) to a dealer who had it for 3 weeks. Bad time of year to be w/o that blue work horse. It had 480 hrs. on the clock so I had them perform the 500 hr. service while it was there. After replacing all liquids and filters - they ran it with a bush hog and had no issues. I got it back 9 June.

Until Saturday it worked flawlessly - mind you the dealership never did find anything specific but changing the filters "appeared" to work. I had a heavy equipment mechanic friend look at it yesterday. We sounded the tank for water - none - then when I attempted to start the tractor it immediately lost rpm almost to stall. He (mechanic) had to pump the primary filter (water separator) so we could get it out of barn. He checked for water in the primary filter - none - so he then removed the fuel pump and using a temporary suction line and wiring to his truck battery. We ran the pump suction line into a full 5 gal. container of diesel then discharged into an empty container. The pump appears to be working as it should. After reinstalling the pump we ran the engine from idle to about 2300 rpm for maybe 10 minutes. All's well. Or so we thought. Once again nothing definitive was done. The mechanic did mention the possibility of air getting into the lines but nothing jumped out at him.

He left and about hour later I was going to put the tractor back in the barn. 3 times I had to get out and pump the fuel filter - once it stalled.
I've spent the day waiting by the phone for a return call from the dealership's mechanic.

So, it appears that my tractor may be experiencing the same issues that you had. Do you know which fuel lines were replaced? Or was it all of them?

bruceatlam · Aug 16, 2016

Have you guys checked/cleaned your air filters?? It needs air just as badly as it needs fuel.

RandyinMS · Aug 17, 2016

xmariner said:
npaden,

Glad to hear your problem was resolved. I too, am having a similar problem. Started (maybe) back in late April or May but it wasn't as severe as your tractor was exhibiting. I trailered the tractor(50 mi.) to a dealer who had it for 3 weeks. Bad time of year to be w/o that blue work horse. It had 480 hrs. on the clock so I had them perform the 500 hr. service while it was there. After replacing all liquids and filters - they ran it with a bush hog and had no issues. I got it back 9 June.

Until Saturday it worked flawlessly - mind you the dealership never did find anything specific but changing the filters "appeared" to work. I had a heavy equipment mechanic friend look at it yesterday. We sounded the tank for water - none - then when I attempted to start the tractor it immediately lost rpm almost to stall. He (mechanic) had to pump the primary filter (water separator) so we could get it out of barn. He checked for water in the primary filter - none - so he then removed the fuel pump and using a temporary suction line and wiring to his truck battery. We ran the pump suction line into a full 5 gal. container of diesel then discharged into an empty container. The pump appears to be working as it should. After reinstalling the pump we ran the engine from idle to about 2300 rpm for maybe 10 minutes. All's well. Or so we thought. Once again nothing definitive was done. The mechanic did mention the possibility of air getting into the lines but nothing jumped out at him.

He left and about hour later I was going to put the tractor back in the barn. 3 times I had to get out and pump the fuel filter - once it stalled.
I've spent the day waiting by the phone for a return call from the dealership's mechanic.

So, it appears that my tractor may be experiencing the same issues that you had. Do you know which fuel lines were replaced? Or was it all of them?

Could be different issue. Your is an XR his is a U could be different engine, pump etc. Mine was doing something similar, but cutting out when hot and trying to pull a load. My issue was the wiring harness to the fuel pump was installed wrong and a hole was worn through and shorting out.

1stDeuce · Aug 17, 2016

This sounds a lot like the issue some Duramax trucks have, and some Jeep Liberty CRD's too. Most newer diesels don't use a tank pump, they just let the IP suck up the fuel, so the fuel system is under suction, not pressure. The Dmaxes can collapse the hose where it bends, and the Liberty's suck air through push-connect fittings that were designed for pressure, not vacuum.

Any loose fitting, hose barb, etc will allow air to be sucked into the system, and it'll pile up in the filter housing, and starve the engine for fuel. The fact that the others are seeing air get into the system, which needs to be purged is telling... If you're constantly bleeding air and pumping it back up, then it's sucking air from somewhere, and you need to figure out where. This jives with what npaden is reporting fixed his tractor.

One thing that's common on dmaxes is that people replace the fuel filter and end up with two o-ring seals between the new filter and the housing... Might be possible on these tractors too?