4020 Running rough

[McKraut]

I have a JD4020 that has been running rough. I was carrying loads of firewood at around 1800RPM and after an hour without any problems, it started running rough and it was losing power.
After a minute or two, it came back up to power but I dropped the load I was carrying and got it back to the barn. I didn't run it anymore that day. I started the tractor back up a few days ago and let it run at 2000RPM in the barn for about 15 minutes without any issue. Then it started acting up and it wasn't running smoothly. It didn't sound like it was losing power, but it was rougher.
I have videos of it running correctly and also running rough. I shot the video right after it started to run rough. I shut the tractor down for 10 minutes and then started it again, and it runs fine. I then shot the video of it behaving.
My assumption is that there is a problem in the fuel delivery, but I don't understand why it is only happening after it has been running for 15+ minutes. If you can guide me through this, I would be grateful.

Thanks
Bob

It says the two files have been uploaded but they don't show up in the preview. I don't think that they are going to be visible but I will still try. They are both <2MB mp4 files.

This post was edited by McKraut on 11/27/2023 at 06:33 am.

 

[McKraut]

[video play=false:029da9881d]https://forums.yesterdaystractors.com/videos/mvvideo111908.mp4[/video:029da9881d]

 

[Roger in Iowa]

Change the fuel filters.

 

[Dieseltech]

Run it again until it starts acting up, then QUICKLY loosen the two screw timing cover on the pump side. If engine runs/acts OK WITH the fuel leak, but acts up with
cover tight, it's confirmed injection pump needs repair. Retainer ring bits are breaking apart inside which plugs the return line side, which WILL cause pump to act up
and upset the advance curve and/or engine to stall. Wait a few minutes and it will start right back up, then act up again. This is where I look if the fuel supply side
is known to be OK.

 

[used red MN]

Hello McKraut welcome to YT! The majority of these
tractors were diesel but were also built as gasoline,
nothing you said indicates a diesel except maybe the
word ..fuel.. which can be generic. So that and year is
good to know. If a diesel as the other poster said
change the fuel filters. If that is not the fix it is very
likely the governor cushion ring in the pump is
disintegrating, running erratic is a common symptom.
There is a guy on here who posts as Dieseltech, he
runs a pump shop in Indiana. Many members here ship
their pumps to him. His charges are very reasonable
and only good things are said about his work quality.
Any video over 15 seconds long seems to be to large
to post here.

 

[matthies]

Dieseltech, that is a late model and might have the short pump, does that have the cover?? By the pic it looks short to me.

 

[Dieseltech]

The short CB pump does not have the two screw side cover like the DB/JDB pumps do. HOPEFULLY he has the JDB pump, and not that morphydite CB pump.

 

[larryanderson]

Long shifter should be 71/72 with tall pump.

 

[McKraut]

(quoted from post at 09:23:36 11/27/23) Run it again until it starts acting up, then QUICKLY loosen the two screw timing cover on the pump side. If engine runs/acts OK WITH the fuel leak, but acts up with
cover tight, it's confirmed injection pump needs repair. Retainer ring bits are breaking apart inside which plugs the return line side, which WILL cause pump to act up
and upset the advance curve and/or engine to stall. Wait a few minutes and it will start right back up, then act up again. This is where I look if the fuel supply side
is known to be OK.

OK, thank you. I will give this a try, I got called in to work this week and I am not off until next Monday. I will let you know how things turn out.
Bob

 

[McKraut]

Sorry, yes it is a diesel. I am working on some urgent problems in the house so I may not be responding right away to any questions.
I just took pictures of the pump yesterday, but can't find them on the phone. Here is a picture from earlier this year.
Thanks for all of the help so far,
Bob

[/img:a2ed6deed0]

 

[Dieseltech]

Morphydite CB pump. For best results replace it with a JDB pump.

 

[dieselade]

could you add a can of seafoam into the fuel? it might help but wont hurt anything.