Help troubleshoot Mule 2510 Diesel fuel problem KAF950-A

[Kyle_in_Tex]

First off, it belongs to my boss and some kids were driving on his ranch. The tank still smells a little like gasoline possibly. Possibly kids put gas in it? He says he siphoned the tank and put on a new fuel filter.

We had to pressure wash it, as the motor was so caked up with west Texas dusty dirt, you could hardly see the engine.

So, I can get it running, idles decent, but when you take off, about when you get up to speed (50 yards) it starts falling on it's face. Like the motor is starving for fuel. It will sometimes die, but if you let it keep running, it will idle roughly at first, then get smoother and after about 20-30 seconds you can take off again for about 50 yards wide open as before.

I took off the air filter's rubber boot so that I know it's getting air. Also cracked each fuel line at the injector to see it squirt and check if they engine stumbled upon loosening. Also drained the fuel filter which holds about 2 cups of fuel.

2007 & Prior Kawasaki MULE 2510 DIESEL (KAF950-A1) Fuel Pump | Babbitts Kawasaki Parts House

on the link, is p/n 16160 seems to be the fuel pump, but is called the fuel filter body as the cannister fuel filter seats on the bottom.

What is the proper way to bleed this system?

Could it be a collapsing fuel line? They are covered with a nylon mesh and I don't see any leaks.

Anybody seen this before?

 

[aczlan]

Try the same run with the cap loose. If the tank is full and the cap vent is partially plugged it could do that

Aaron Z

 

[Kyle_in_Tex]

Try the same run with the cap loose. If the tank is full and the cap vent is partially plugged it could do that

Aaron Z

Thanks! Just did that. Nothing different.

 

[aczlan]

What does it do if you rev it in neutral? How about if you rev it on jackstands so that all the tires are off the ground?

Aaron Z

 

[Kyle_in_Tex]

Let me check that and get back. Thanks!

 

[3930dave]

Still sounds like fuel starvation.

With kids goofing around, there might be plenty of crud in the tank. Thinking the outlet screen may be getting obstructed. You may have to clean the tank/petcock if it looks chunky in there. If it's bad, you may need a few fuel filters.

Rgds, D.

Edit - is there a pressure test port (valve) on the injector line ? If the tank is clean, you may want to check the rail pressure under load. I don't know what it should be exactly, but you'll be watching for it to drop.

 

[Kyle_in_Tex]

After about forty eleven suspicions, I think I have found the culprit but not the final fix yet. The fuel pump body, which is what the fuel filter seats into, has the manual plunger on top. I finally noticed that it is "sucking" down as the engine gets starved of fuel. This means that either the fuel filter is clogged, the pump's internal valve is stuck, or there is an obstruction in the fuel tank or line that supplies the fuel pump body. I took off the rubber fuel line and it was clear. Ran out of time today. However, I did play with the manual pump a bunch and tightened up a small phillips on top of the button. It seems to be working somewhat now. Will look at it tomorrow and possibly dis-assemble the fuel pump body. There are no parts to buy to rebuild the body, so if I can't fix it, will need to buy a new one.

I even took the muffler off to check for mud dauber nests because I've heard of them clogging up a muffler.

 

[aczlan]

Sounds like you may be onto it...

Aaron Z

 

[Kyle_in_Tex]

Ok for those guys who happen across this thread in the future, I ended up putting all new fuel lines on it. I went and bought 10' of line from NAPA and re-used the fancy protective covers that came with the OEM lines. I also blew a very small amount of air into the fuel tank from both tubes. I listened with the cap off for bubbles and for possible blockages and it seemed clear. Before I put the manual fuel pump and fuel filter back on, I cleaned it and put a few drops of 3 n 1 oil on the primer shaft. Then I primed it and she is running fine now.

 

[Industrial Toys]

I had the exact same thing happen last year around this time. Never had a problem in ten years and then a pile of trouble. Mule 2510 Diesel. Idles good and then dies when you try and drive off. Much of it was fuel issues. Like many problems, it was more then one thing and in the end, you never really know. You try something and it seems to fix the trouble, only to reappear! Changed the fuel filter, removed the tank and cleaned thouroughly. The tank thing is when my problems disappeared. I was sure at one point that the fuel pump was the culprit, but fortunately it was not. Never touched the lines except to check them for blockage.

I have a lot of fuel on hand at any given time. Always a mixture of summer and winter diesel, and you never really know what it is. That and water from condensation. I think it's important to have a good filter on your bulk tank. I have found that conditioner is a MUST. Especially for lubrication in these days of low sulpher fuel.

Had issues with other equipment just yesterday. Thought maybe I had a blown head gasket, as the machine was chugging and coughing white smoke. Another machine was just running really rough and was thinking about calling a mechanic. AGAIN, it turned out to be a fuel quality issue.