Old School Type Diesel Question (Kubota) Final Update.

[Fordum]

Folks, I have mentioned my Cardiologist friend before. He is a truly brilliant doctor, but I have to watch him around electrical and mechanical equipment.

He also has a strange habit of asking me what is wrong with something, refusing to believe I am right, and taking it to someone else.

But, he always speaks right up if it turns out I was right and apologizes.

Don't know how this one is going to turn out.
He sent me an E-mail about his Kubota tractor.
3 cylinder 23 horse hydrostatic drive with a belly mower.

As far as I know, its all mechanical injection, no computer, nothing else.

He had some water problems a couple of years ago, but its been running fine lately.
He said that it had been running fine for about an hour, had plenty of fuel. On level ground, with almost no load on the mower, it suddenly coughed black smoke and died.
Now it turns over fine, and coughs some black smoke like one cylinder is trying to fire, but will not run.

Its not all that old, I would not expect a major mechanical breakdown like a camshaft, or anything like that.

I told him it sounded like he sucked a bird into the air filter.

I told him to check the air filter. If it was good, look closely for any fuel leakage at all.
If anything came loose between the injector pump and injectors, he should see the spray.
But if a fitting came loose on the other side of the pump, all he is going to see is a slight leak, but it would let it suck air.

I reluctantly told him he could try cracking the nut where the line goes into an injector and look for air bubbles when cranking.

I doubt I will get a chance to actually work on it, but if I do, I'll post back.

Meanwhile, if anyone has any other ideas, let me know. I'm sure I will find out what is wrong when he gets it fixed, and I'll post that here too.

 

[TheBeast_88K5]

So THIS is how you get these stories....

 

[Fordum]

So THIS is how you get these stories....

Yep.
One of the funniest ones, was when he called me because one of the air conditioners on his big cabin cruiser had quit.
He and a bunch of our friends were going on a 3 day fishing trip, and the main AC kept tripping out on high head pressure.

I was sitting on top of my 8N Ford tractor in the middle of my field talking to him on my cell phone.
He was 30 miles away at the marina about to start out.
These are big built in central type units, water cooled.
I listened to the symptoms, and told him what to do.

I told him to have my cousin, baitfish2 who was going with him, put on his swim trunks and go over the side.
Feel around and pull the plastic bag out of the water intake for that AC.

I knew it was most likely something stopping up the intake, but the plastic bag part was a wild guess.

He assured me that he could see the end of the intake under the water, and there was noting stuck to it.
I assured him that it was there, and if they did not do that, there was nothing further I could do since I was too far away.

They just shut down that AC and went fishing anyway.
Had a lot of fun, but they all had to sleep in the forward cabin and rope locker, because it used a separate AC and it worked.

Few days later, he called.

Said he hired a local marine AC repair shop to come fix it.
They cranked up the engine, ran it for a few seconds, and then one of the guys hopped over the side and pulled a plastic bag out of the intake...........

What can I say? I'm just that good.........

 

[TheBeast_88K5]

There are only so many things that could be wrong with a machine.
Don't you wish people would just listen to you, sometimes.

I mean, it's their dollar, but c'mon...


Yesterday, I watched a guy overfill the gas tank of a (50's-60's?) DeSoto.
He was on the side of the road.
I stopped to help, but he assured me that, "It just needs gas."

Funny, didn't know you could diagnose a fuel issue.... with the car not turning over.

I went along my merry way.
Not like I know anything about basic engines, or anything.

 

[zombiyjay76]

I just went through an issue with a Kubota engine that we have on one of our fire trucks. It would not start, would just crank, we tried to bleed the lines but no fuel coming out of any of them. Then we pulled the fuel cut off solenoid out, and the thing fired right up and ran great. Replaced that and now its running like it should, but this is on a 4 cylinder. Pretty sure it should work the same though.

 

[Fordum]

I just went through an issue with a Kubota engine that we have on one of our fire trucks. It would not start, would just crank, we tried to bleed the lines but no fuel coming out of any of them. Then we pulled the fuel cut off solenoid out, and the thing fired right up and ran great. Replaced that and now its running like it should, but this is on a 4 cylinder. Pretty sure it should work the same though.

I suspect you have nailed it. A solenoid failure or the wire coming loose would cause just the symptoms he described.

I have since gotten a new message from him, and it indicates that the solenoid is more likely than ever.

It also demonstrates why my friends need me......
I can't improve on his message, so I present it here.

Went back up to the Kubota and changed the air filter which did not look too bad at all, but I had a spare and installed it.

I had a fuel filter, so I took that off and changed it. I ran the pump to fill the filter prior to closing it up, but no fuel. I reattached the line and tried to crank the engine, but it would not fire.

I decided that I needed to take it to the dealer, and to that end had taken my flatbed up with me.
I backed it up to the tractor, but had no way to load it.
I put a cement block in front of both sides of trailer wheels and unattached the trailer from the 4Runner.
I then took a pulling strap from the trailer hitch on the 4Runner to the tractor to pull it up on the trailer.

The stupid scheme worked to a degree, but both trailer tires became airborne over the cement blocks when the weight of the tractor loaded on the rear gate, and the whole works threatened to run downhill to the truck when I stopped.
I tried to move it sideways with a comealong, but that was too inefficient. Licking my wounds, I ceased operations and returned to town.

I think I will get a friend with a winch to pull it on while the trailer is attached again to the 4Runner.

Guess who the friend with a winch is..............

 

[zombiyjay76]

Yup, sounds like a doctor to me. Tell him to pull the solenoid (2 bolts and wire connection) and see if it starts. And if it does there is a shut off lever on the fuel rail to shut it down. I'm sure its not the professional way, but that is how I found my problem.

 

[Fordum]

How does the solenoid stop the fuel?
All the solenoid valves I have worked on, had a plunger that stopped up a hole. If you took the solenoid off, the fuel would run out.

It will probably be obvious when I see it, I have certainly figured out more complicated things than that, and I suspect I will be the one working on it.

But if he calls instead and asks, it might help to have an idea of what I am telling him.

 

[Fordum]

Ok, got smart and looked up the stop solenoid on a BX2660 tractor. It looks like the plunger goes into a hole and plugs it.
If I'm right in the way this thing works, I can pull the plunger out and put the coil back on to stop the leak.

Either way, I feel sure I can bypass it somehow if I get a chance.

 

[zombiyjay76]

You're right about how it works, just a little plunger inside the housing that stops the fuel flow. I too thought it would flow out, but I didn't see any fuel. I still kinda scrambled to get it shut down though.(figured it wouldnt be good for it to run with the solenoid off) I only let it run for about 30 seconds, but it fired up real quick with solenoid out of the way. Don't know why there wasn't any fuel spraying from it. Maybe Demon will chime in on the specifics.

 

[zombiyjay76]

Beat me to it, let us know how you bypass it. Would be nice to know that info if we are on a fire and that thing goes out again.

 

[Fordum]

Well, got the call this morning. The good doctor was headed up to the tractor and would I come help him load it?
My truck was not available, so I grabbed a short strap and my 8 ton snatch block. Had some pretty strong rope in the car.

When I got there, I checked out the solenoid. It is mounted on the injector pump, and I don't think it is a solenoid valve.
Its called a stop solenoid, and I suspect it moves a spring loaded valve inside the pump to stop the engine.
It was clicking just fine, plus the main problem was obvious. Lack of fuel in the inline filter.

I tinkered with it a little while, and I'm pretty sure I could have fixed it. There is an obvious blockage in the line from the tank, or inside the tank its self.
But, he wanted to just go ahead and load it on the trailer and take it to the shop.

The mower deck is raised hydraulically, and I got the engine to sputter along a few seconds at a time in idle.
But it would not run long enough or fast enough to raise the deck.

The doctor had some 3/8 or 7/16 rope, so I strapped the snatch block to the front of the trailer, and ran the rope from the back of the tractor through the block and tied it to the back of my car.

I rolled down all the windows and left the back gate up so I could hear him.
The trailer was at right angles to the driveway, so I just eased up the drive watching him in my mirror.
As the leading edge of the mower deck reached the level of the trailer bed, I saw it piviot.
Told the doctor, and he walked around and found the deck had dropped down between the tailgate/ramp and the trailer body. He lifted it up and it hopped up on the bed.

After that, it rolled right up as I pulled.

So, it is at the shop, and he will let me know what they find. I'm betting on a piece of trash such as the seal off a bottle of stabilizer or a large bug.
Some friends of mine once found a dead hornet in the fuel line of a D4.
No idea how he got there.

 

[Fordum]

Well, he just called. They know him at that dealer, and he is the type who just buys new instead of doing a lot of repair, so they like him a lot.

As a result, they jumped right on it while he waited, and the final verdict is, "lots of crud in the fuel tank".
It lives in a closed, climate controlled building, so rain is not a factor, I'm going to grab him a small bottle of algacide for diesel and tell him to pour in a few drops every-time he fills it up.

It sits up a lot, and I suspect he has some growth in there.

 

[zombiyjay76]

Heard of that crud before, never seen it. Or know any one who has had an issue with it.