4120 engine surging and then stalling

[tinsnip]

Greetings! Hope the weather where you are is as pleasant as it is here today.

Yesterday, after using my York rake for about an hour, I shut the 4120 down and filled it with diesel then went in for lunch. When I returned and started the tractor, it ran fine for about 15 minutes then began to surge. The tach would ramp up to 2500 and then down to 1500 while the throttle lever was set at about 1900. When I put the throttle lever all the way down, it would stall. I restarted and limped it back to the shed where it sat overnight. This morning, I bled the fuel filter and it started and ran for about an hour. I thought I'd solved the problem so at that point I parked it and shut it down. 30 minutes later, I started it up and the same problem occurred.

Is it possible the diesel is bad or dirty? What other components should I check?

As always, I appreciate your helpful replies.

Thanks!
Tim

 

[dusty3030]

Reverser or E Hydro.

 

[tinsnip]

Reverser or E Hydro.

E Hydro.

 

[dusty3030]

Ok could be load match / electronic issue and not fuel related at all

 

[aginn]

Sounds like water in the fuel filter to me. I'd replace the filter before you get too carried away.

 

[dusty3030]

Sounds like water in the fuel filter to me. I'd replace the filter before you get too carried away.

Is there any water in the bottom of the separator when you drain it. Does any water drain out or fuel or combination of both.

 

[tinsnip]

No water in the fuel when draining the filter. I started and ran it for about 45 minutes before symptoms re-occurred. Could heat be a factor? It will run strong and steady and then all of a sudden start to sound odd (like running on only one cylinder) and then range all over the place, racing then slowing down, etc. I was hoping it was as simple as bad fuel, but I don't understand how it could run so well for the first 45 minutes if that were the case.

Thanks for your ideas.

 

[dusty3030]

For giggles run it with the fuel cap loose I think ours has a vented cap correct?

 

[tinsnip]

I'll try that in the morning. I'd love it to be something simple.

Thanks!
Tim

 

[tinsnip]

I've run it for about 45 minutes without he problem re-appearing. Plan to run some more today.

 

[tinsnip]

I'm re-awakening this thread since the problem persists. I thought I had it licked after replacing the fuel filter (twice!). I've had it running straight for over 2 hours at a time but just today, it started all over again.

The consensus from the guys hanging around the Dealer's counter is that there's some dirt in the fuel tank that needs to be cleaned out. Does anyone know where I can find an exploded view diagram of the fuel tank and/or directions on how to best drain and clean the fuel tank?

Also, what, if anything, exists in the fuel line between the tank and the filter? Is there another mechanism I might be overlooking?

Just to be clear, the fuel is fresh and the filter is brand new as of 1 hour ago. I'm not seeing any kind of message on the readout except "default" and when it runs, it purrs. And then suddenly it will change tone, blow black smoke and the engine pulses. Throttling down all the way uses causes it to stall. If it sits for 30 minutes or so, it will restart and run for a completely unpredictable amount of time.

Thanks for your help.

Tim

 

[beenthere]

You can view the schematic of the tank and associated parts on jdparts.com (free registration). Just type in the model # and then find it on the list... click and then go to alphabetical listing under F for fuel tank. You will see the lines there.
As to cleaning... various ways but I'd disconnect one of the outlet lines at the most bottom point to drain.. then rinse well.
Sounds like debris in the tank. Maybe even algae.

 

[Tx Jim]

tinsnip
Did you try operating with fuel cap loose/absent as dusty3030 suggested?

 

[tinsnip]

Thanks for your replies. I'll check the schematic and attempt the drain and clean tomorrow. And yup, I tried loosening the cap several times and it made no difference. Thanks again.

 

[tinsnip]

Just to beat this to total death... I'm still struggling for a solution to the original problem. I've completely drained the fuel from the tank, replaced the filter, then filled the fuel with diesel purchased at a different location and used a brand new fuel can (just to eliminate the possibility of contaminated stuff). All other fluids and filters are new and/or in top notch condition. But once again, at about the 1 and 1/2 hour mark, the engine began to stumble, then surge, with a big loss of power. I did notice a clicking sound but am not enough of a diesel-head to know what's causing it. Is there an electrical solenoid somewhere that might be failing or overheating?

I'm pretty much at the limit of my paltry mechanical abilities and about ready to trailer it into the JD dealer so they can suss it out. Paying them to come out here is out of the question (big bucks!).

 

[arlen4720]

There is a fuel solenoid of course. That could be dropping out.

 

[tinsnip]

I replaced that last year. Is it possible that it's bad again or was installed improperly? Could the length of time be influencing its function? I t runs like new right up until the point it dies, which is almost always at around 1.5 hours. Heat? Thanks for your interest and ideas.

 

[tinsnip]

Just to close this out. Ended up taking it in to the dealer for service. The mechanic drained the fuel into a bucket and said he saw orange mixed in. He thinks there was gas contaminating the diesel. He said that the gas makes the fuel burn hotter and that after awhile, the injectors would heat up and begin to fail. Hence the loss of power, smoking, and surging.

I had drained it myself but into narrow-mouth cans and never looked at the fuel. Since he had blown out all the lines and probably did a better job of draining it completely, I think he managed to remove any traces of the gas that was still trapped in the system. It's now back to running fine and I'm hopeful that this episode is over.

I had been buying my off-road diesel at the small general store here in town. They have two diesel pumps, one for clean diesel and one for off-road diesel. The ORD is one side of a two-hose pump. One of those old-style gas pumps with a hose/handle on either side. If I was to guess, I'd say that the wholesaler accidentally started putting gas into the wrong in-ground tank. But that's pure speculation. Regardless, I'll be buying my diesel elsewhere.

Fingers crossed that this episode is over and I consider it a valuable lesson learned.

Tim

 

[beenthere]

I take from your experience that I will stay away from off-road and continue to buy diesel from the pump that the truckers use. The few penny's saved with the off-road coming from a seldom-used pump/tank can end up being costly. Thanks for the "lesson learned".

 

[arlen4720]

Just to close this out. Ended up taking it in to the dealer for service. The mechanic drained the fuel into a bucket and said he saw orange mixed in. He thinks there was gas contaminating the diesel. He said that the gas makes the fuel burn hotter and that after awhile, the injectors would heat up and begin to fail. Hence the loss of power, smoking, and surging.

I had drained it myself but into narrow-mouth cans and never looked at the fuel. Since he had blown out all the lines and probably did a better job of draining it completely, I think he managed to remove any traces of the gas that was still trapped in the system. It's now back to running fine and I'm hopeful that this episode is over.

I had been buying my off-road diesel at the small general store here in town. They have two diesel pumps, one for clean diesel and one for off-road diesel. The ORD is one side of a two-hose pump. One of those old-style gas pumps with a hose/handle on either side. If I was to guess, I'd say that the wholesaler accidentally started putting gas into the wrong in-ground tank. But that's pure speculation. Regardless, I'll be buying my diesel elsewhere.

Fingers crossed that this episode is over and I consider it a valuable lesson learned.

Tim

Glad you got it figured out, and you're lucky it didn't tear up the unitary injector pumps. Maybe the dealer serviced them?