Diesel Engine Trouble

[Dustin]

I have a Kubota M5700 with about 350 hours on it. I've owned it since new. It has a five cylinder non-turbo diesel. Aside from the power steering and hydro transmission always freezing up in the winter (yes, I'm running the lighter weight fluid), the engine has recently started to have a problem. The hydraulics eventually warm up and work, so I'm really concerned about the engine right now.

The engine condition is that it fires right up, no problem, but after about 15 minutes it begins to skip and loses nearly all power, feeling like it's running on only two cylinders, and it will eventually stall. I can shut it down, wait a minute, and start it back up and it's fine for about another minute before the skipping occurs again. I changed the fuel filter, added Power Service cetane boost and anti-freezer and it seemed like it worked for a little bit but then it was back to this skipping. I don't know what to do next. Any thoughts? Suggestions?

 

[davesl708]

I am not that familiar with the M5700 but my Kubota has two fuel filters. One near the fuel tank and one near the engine. Sounds like you are starving for fuel or the injectors are fowled. Might look for the other filter and see if it is gelled and run some PS911 through it to clean it out.

 

[Leejohn]

Check air filter then check fuel tank fill cap vent.

 

[Egon]

After the fuel situation is cleared up you might consider looking at the transmission fluid.

 

[Dustin]

There is only one fuel filter on this tractor and I already changed it. Thanks for the comment

 

[JerryK]

My Mahindra Bosch injection pump has a KSB solenoid [ and associated timer at a remote location ] that advances the engine timing a bit during the timed period to assist in making it start easier. If the basic engine timing is off, the tractor can run great during this ' KSB time ', then run like krap after that. If your tractor has a KSB, the timer contacts could be stuck ON... or your basic timing could be off... If your tractor does have a KSB, try taking the connector off when it start running rough and see if she settles down. Note that the injector pump usually has a fuel shut off solenoid, too. Unplug that, and she will die.....

 

[Patrickdozer]

I agree with what has been said here. There is a product called Seafoam, comes in a white can and available at Walmart or auto parts stores. I use this in car and outdoor equipment. It is safe to use in diesels and it is a injector cleaner. May be worth a try with the rescue 911 like dave suggested. Other than that seems like an injector problem provided there isn't a defect in fuel pickup or line.

 

[KYDan]

Are you using any additives in your fuel and are you using off road diesel fuel? Do you store fuel at your place or buy fresh fuel regularly? I noticed you are in New England and this has been a cold winter. Fuel gelling could be part of the problem. If you are using stored fuel do you filter it with a water separating micro filter?

 

[Dustin]

Are you using any additives in your fuel and are you using off road diesel fuel? Do you store fuel at your place or buy fresh fuel regularly? I noticed you are in New England and this has been a cold winter. Fuel gelling could be part of the problem. If you are using stored fuel do you filter it with a water separating micro filter?

No, no fuel additives prior to the problem beginning. Not off-road diesel. Yes, we get fresh fuel regularly. I thought about the fuel gelling, but it starts up without a problem. The issue only comes after operating for 10-15 minutes.

 

[Dustin]

My Mahindra Bosch injection pump has a KSB solenoid [ and associated timer at a remote location ] that advances the engine timing a bit during the timed period to assist in making it start easier. If the basic engine timing is off, the tractor can run great during this ' KSB time ', then run like krap after that. If your tractor has a KSB, the timer contacts could be stuck ON... or your basic timing could be off... If your tractor does have a KSB, try taking the connector off when it start running rough and see if she settles down. Note that the injector pump usually has a fuel shut off solenoid, too. Unplug that, and she will die.....

Thanks, Jerry. I will check on this.

 

[Xfaxman]

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The engine condition is that it fires right up, no problem, but after about 15 minutes it begins to skip and loses nearly all power, feeling like it's running on only two cylinders, and it will eventually stall. I can shut it down, wait a minute, and start it back up and it's fine for about another minute before the skipping occurs again. ----------- I don't know what to do next. Any thoughts? Suggestions?

Check air filter then check fuel tank fill cap vent.

When it starts to lose power remove the fuel cap. The vent might be frozen shut.

If there is no vent in the cap, find where the tank is vented and fix it.

 

[Dustin]

When it starts to lose power remove the fuel cap. The vent might be frozen shut.

If there is no vent in the cap, find where the tank is vented and fix it.

It's interesting. Today was in the mid-30's, so I drained all the diesel, filled it with new diesel and it ran like a champ. The problem is, the fuel that was in the tank was all new fuel as well. I'm thinking maybe it was a frozen tank vent that thawed in the warmer weather?

 

[Dave M7040]

Dustin
I have a M7040 and in the owner's manual there is a chart for the warm up time before using the tractor.
This is primarily to allow the hydraulic system to warm up. It can be as long as 20 minutes at very cold temps and has to be at a high idle for which I find 1500 the best for a smooth run.
On my tractor there is one hydraulic system which even serves the power steering and hydraulic shuttle.
If your system is the same and you are not warming it up it could explain the steering and transmission problems you are having.
Dave M7040