Mustang/Gehl/Neuson Excavator shutting down every few minutes

[john146]

My mini excavator has recently started shutting down every few minutes; it seems to happen more often if I'm using it - it usually, but not always shuts down when I'm in middle of engaging the ground, but sometimes will also shut down when it's idle. I've checked fuel flow-- the air filter, fuel filter, are new. Fuel pump seems to be working fine; drained water separator.

After it shuts down it won't start right back up; I usually need to wait about 20-30 seconds; then it will run for about 5 seconds and cut out; then starting it about 15 seconds later will let it run well (for a few minutes, and then it shuts off again)

Maybe an overheating issue, but I'm not seeing the temperature sensor light coming on; fan is working perfectly (though the belt could be tighter). I also just topped off coolant. There is ample airflow in the engine compartment though.

 

[thepumpguysc]

Engine type?? fuel system type?? Does it sputter & surge like its fuel related or just a key switch shut down.?? How was the water sep.?? full of water..
U sure left alot to the imagination..
Take the fuel cap off.. & see if that helps.

 

[john146]

It doesn't sputter or surge, just dies gracefully.
The engine is a Yanmar Diesel 3TNV88. I have the service manual for it. The separator didn't seem to have any water in it. The thing actually doesn't have a fuel cap.

Could be a bad stop solenoid? Would that cause the weird restart issues I'm seeing too?

 

[KSSS]

Given the time to reset it sounds like a safety switch, not sure if that motor has such capability or not but maybe a low oil psi switch or coolant.

 

[john146]

I was thinking about a sensor switch, however, when it did overheat (if the belt tension is too loose, so the fan doesn't blow fast enough), the light simply came on, and the engine just kept running. I don't think it has that kind of capability.

Likewise regarding oil pressure, there is no indication there is an emergency shutoff functionality.

I am realizing it's eating coolant, though.

One more thing I should note, I recently heard it surge almost to off, and then go back up, but not in a continuous pattern. I'm still not sure what's responsible for it, but as far as I can tell, the fuel system is free of obstructions.

 

[Bls repair]

Is fuel tank venting?

 

[Ronsii]

Our case mini with the same engine in it would do similar... although kinda random on the times of how long run and how long wait... I went though all the troubleshooting thinking it was something electronic... fuel shutoff... took fuel shutoff out of the motor (2 bolts) and it would still do it.... turned out to be air getting in the fuel - put a piece of clear fuel line in the system after everything and you will confirm this.

 

[john146]

It turned out to be an obstruction in the fuel line. Why it didn't actually feel like it, I don't know. Drained the tank twice, but I think what actually helped was blowing compressed air through the line. I think there were several BIG pieces that were somehow making their way.

Now I have a burst hydraulic line. These things always seem to happen one after the other!

 

[thepumpguysc]

Funny u should mention that..
I took off & rebuilt a pump today..
Put it back on & the owner text me 30 minutes later & asked where to get a hydro line made up..
It blew as he was doing some warm up lifts..

 

[Coastal]

It turned out to be an obstruction in the fuel line. Why it didn't actually feel like it, I don't know. Drained the tank twice, but I think what actually helped was blowing compressed air through the line. I think there were several BIG pieces that were somehow making their way.

Now I have a burst hydraulic line. These things always seem to happen one after the other!

I wish I had seen this earlier! Mine does the same thing, there is a bit of crud in the fuel tank, if you let it run low it all makes its way into the fuel outlet and plugs it up. I usually pull the fuel line off before the filter and use my lungs as a compressed air source and blow it out. Glad you figured it out.