Kubota Excavator V1505 motor Fuel Delivery Problems

[ricknrolling]

I have a k030 Gray Market Model. kx-91 USA Equivalent. Have had not problems with parts including tracks as long as you do all your own homework. Installed new tracks, and motor was rebuilt by previous owner and ran for several months until it developed some sort of fuel delivery issue. I acquired with no hoses installed. Installed all new hoses, filters, and lift pump. Starts and runs great and is maxed out at 2000 rpms until you put a load on it. Then it bogs down. Have checked for air leaks in the hoses. Doubled up the clamps. Still same problem. Drained tank, cleaned it all out. Good flow. Still does the bog down. The injector pump had been removed and reinstalled by previous owner. COuld something be goofed up with it being reinstalled? Like could it need to be turned up? Let me know any thoughts. Not sure if I can upload a video of what it is doing. Let me know if any of you have encountered this on a Kubota and what you did to remedy it.

 

[1970cs]

As far as general knowledge on engines, I would suspect a governor issue. My dealerships has nothing to do with the industrial line from Kubota. You need a WSM from kubota on the engine to due the adjustment.

Pat

 

[North Idaho Wolfman]

There is 2 adjustments for the governor and if either has been moved then it will have to be re done and set up properly.
Now as far as the injection pump, if all the sims were not installed or if the spring were not reinstalled that could have a bearing.
Also if the injectors or the pump is malfunctioning that could cause it.

My recomendation would be to get the WSM for the V1505 Go here, and get it, http://www.promacinternational.com/wp-content/uploads/2012/02/Kubota_Workshop_Manual.pdf

Then I would pull the injection pump and the injectors, send all of the parts to Oregon Fuel Injection and have them test them out for you.

 

[ricknrolling]

Cool I will study the manual. See if anything might be obvious with the governer adjustment. Little hesitant to pull it as I have heard stories of reinstallations going wrong. Like out of time improper shimming. Although that could be what's wrong with it anyhow. I would think timing is ok though because it does run and idle good until put under a load. When I accelerate the throttle it is sort of delayed response before it goes from 900 to 2000. Seems like it should rev much higher to. I suppose it very likely could be governing issues. Thanks for wsm link.

 

[ricknrolling]

Here is a video link to show you what's happening

http://youtu.be/QObuBSYfo_U

http://youtu.be/QObuBSYfo_U

 

[rentthis]

I have had dozens of non-grey market Kubota excavators. One common fuel delivery problem is in the fuel water separator ie fuel filter assembly. If yours has the same filter assembly as mine, replace it and the problem goes away. The pipes where the fuel lines connects get loose and suck air. You can test it with JB Weld. Put the JB around the pipes where they go into the body of the filter assy. Let it harden and then give it a try. If that corrects the problem, replace the assembly. The JB is at best temporary. I have done this successfully 7 times now.

 

[Billdog350]

I have had dozens of non-grey market Kubota excavators. One common fuel delivery problem is in the fuel water separator ie fuel filter assembly. If yours has the same filter assembly as mine, replace it and the problem goes away. The pipes where the fuel lines connects get loose and suck air. You can test it with JB Weld. Put the JB around the pipes where they go into the body of the filter assy. Let it harden and then give it a try. If that corrects the problem, replace the assembly. The JB is at best temporary. I have done this successfully 7 times now.

i've seen this before as well, X2 ith rentthis. Do the test he suggests and see if it solves the issue. Cheap test to run!

 

[North Idaho Wolfman]

It's funny that rentthis, and Billdog350 brought this up, because i thought of it right as I was logging in.

I would just bypass the whole thing and feed clean fuel directly into the injection pump and see if that eliminates the RPM loss.

 

[ricknrolling]

Thanks for the feedback. I really appreciate it. I did bypass the fuel water seperator thinking that perhaps it was drawing air. Because it looks old and deteriorated. But this did not have any change. It's setup so that the lift pump draws from filter to the injector. But have wondered if it's better to have the lift pump between the filter and tank so that it more less pushes through the filter and out to the injection pump.

 

[ricknrolling]

Purchased a whole new fuel/water separator and just installed it this evening. Bleed all the lines and injectors. Still same thing. Thought I would try and look at the governor. Not much daylight left so I thought I would first try adjusting the throttle cable to get the slack out of the cable when at idle. It changed the idle speed from about 850 to 1050. At max throttle I was at about 2250 RPMS. Sounded good. So I started to put a load on it. Wow! It actually did not bog down. Took it on a little move and used the bucket. After I turned around to put the excavator away, the bogging down started all over again. Not sure if it was a coincidence that the cable adjustment seemed to fix the solution or not. Still think something is messed up in the injector pump. Looked at the WSM. A little intimidated to pull the plate off. Please let me know if you have any additional thoughts after this new update.

 

[North Idaho Wolfman]

I would still directly feed fuel into the injection pump from a bottle or some other sorce than the fuel tank.
I would also pull the return line off of the injectors and open that up.