JD2020 Diesel Low Power Issue

[codeman020]

Howdy Yesterday Tractors Friends!

I have a 2020 John Deere that is new to me this year. I normally use the tractor to move round bales between barns and its usually well behaved - ive also used it on the pull behind rake without much trouble.

But I have had 2 instances of this (Once while bush hogging and the other today while trying to push snow with it -- both instances where using the 3pt).

What happens is it will start and come to temprature, then with the throttle at full the RPM will slowly walk its self back until its unable to maintain 1000rpm. Shut it off and relight and it comes back to full power and slowly dies down again. I suspect I need to do a service on the fuel system but im wondering if anyone has encounted this before where it could be something more to it like the fuel injection pump or injectors possibly? Needless to so im parking it until better weather to do the fuel filters and check the lines are not getting clogged at the tank etc.

Open to anything else i might be missing.

Stay warm!

 

[Tx Jim]

Loosen the 2 screws(item 24) that retain the timing window cover on your tractors inj pump. Pry rubber gasket from IP housing so fuel leaks out. Now start engine & if engine will maintain rpm's then probably check valve in fitting on IP that return line attaches to is clogged. Drive ring inside IP is deteriorating & IP will require disassembling to replace drive ring

 

[Dieseltech]

Xs 2 what Tx Jim said, loosen the timing cover on the pump side, if engine runs OK WITH the fuel leak, it's confirmed, injection pump needs repair. DO NOT knock out the return fitting check ball and keep running engine, or eventually the retainer pins WILL shear off, hydraulic head WILL seize and then break the drive shaft...

 

[Tom in Mo.]

You don't mention ambient temperature where you are. If it's +10 or below it might just be fuel gelling or clog in fuel delivery. Gelled fuel acts just like this until it blocks up everything.
I'd be checking the simple things like fuel delivery before mechanical things.

 

[Resting Relic]

Good Morning,
Pretty common issue on tractors with a RosaMaster injection system that have a lot of hours or just getting old. The drive ring in the pump is coming apart and the pieces get lodged in the back flow fitting on the return line leaving the pump. As others have said the test is fairly easy. Back when I worked on these I had a fitting I would substitute with the fitting with the ball in it and test run it. Almost always it would run fine. The problem is if you run it for very long, eventually that drive ring will fail with serious damage to the pump, usually a complete replacement will be needed. It's hard to say how long. I've seen them run another thousand hours while others might fail in less then 50. Best to pull the pump at your earliest convenience and get it rebuilt. Good Luck! John

 

[codeman020]

Thanks All for the feedback.
Ive had the issue at 25C and recently in the -10C. I'm fairly sure it will be the pump and I will test it when the spring weather comes.

Appreciate all the feedback and have a great day!