John Deere 410 Backhoe Fuel Issue--Dieseltech?? Others??

I have a 1983 JD 410 Backhoe. On Saturday while digging with it, it started to lose power and rpms. I throttled it down and then back up. When I throttled it back up the RPMs did not increase, it was running at idle speed despite the throttle being wide open. The engine then died. I waited about a minute and then tried to start it again. It started immediately and ran for about a minute and then died again. It seemed like it was running out of fuel, but the tank was about 3/4 full.

My first thought was the fuel filter was plugged so I got a new fuel filter and also changed the fuel pump on the side of the engine. I did not think the fuel pump was bad, but it was leaking oil below it and was only 25 dollars at John Deere so changed it. While changing the pump it would run a full stream of fuel out of the line coming from the tank to the pump. I got the air out of the filter and started it. It started immediately and ran a bit rough at first like there was some air in the line, but smoothed out after about 15-20 seconds. It ran ok for about a minute or two then did the exact same thing as on Saturday, it loses rpms and then dies. It will restart immediately, but will only run for about 30 seconds before dying again.

I drained all the fuel out of the tank and blew up the line to the tank with an air tank to make sure there was nothing partially plugging the line. The line blew very easily and there did not seem to be any obstruction in the line. I then put fresh fuel in it and tried to restart it. It again would start immediately and run for about 30 seconds and then die.

The fuel I drained out of the tank was purchased about 2 weeks ago at what I would consider a reputable station near me. It is offroad diesel/heating oil. I have a Case 1030 with the same fuel in it and runs fine. I don't think it is the fuel. The new fuel I put in is on road diesel from a local Sheetz station, again pretty new fuel in that it was purchased about 3 weeks ago.

Any ideas? To me it acts like a fuel starvation issue. I have a good flow of fuel from the tank to the fuel pump and a new pump. I'm wondering about something with the injection pump or the solenoid that shuts the fuel off. It does not have what I would consider a normal fuel shut off lever and shuts off with the key.

check the return line, if it is blocked you will get these exact symptoms.

Do you mean the return line from the injectors?

Start engine again, and loosen the two screw timing cover on pump side. If engine runs fine WITH the fuel leak, but acts up with cover tight pump needs repair. The retainer ring is failing inside the pump which will cause shut down at return fitting and/or return line. DO NOT knock the return check ball out and keep running engine, retainer pins WILL shear off and seize the hydraulic head, and break the drive shaft.

Just to make sure...can I loosen the cover and then start it, or do they need loosened while it is running?

I've never done anything on an injection pump before.

I presume this is the timing cover?

Id loosen the cover to make sure it will leak first, then tighten it back up. Now start engine and have the screwdriver ready to loosen it up again JUST as engine speed begins to drop. If speed picks back up WITH the leak, its confirmed that pump needs repaired. I just finished repair and calibration on a 4020 pump in for the same trouble

What sand castle is talking about is the return line off the pump. I believe it tees in with the injector returns at some point. Should have a line feeding the pump from the filters and the other line is the return. The check Dieseltech is having you do will cover checking this problem. The problem is likely with the governor ring as he has told you. There is a slight possibility that the return to the tank is the problem if it runs much better after loosening the timing plate and slows down again after a little bit, you could loosen the return line at the pump then run it to see if it solves it. If it does run better with the line loose your return to the tank is plugged. If that is so you will get by cheaper but that problem happens far less unlesss the line got smashed some way. I suspect you know you can ship your pump to Dieseltech for a rebuild, he has an email in Classic.

There is a line from the filter to the injector pump. There are four lines going up to the injectors and a return line from the injectors back to the injector pump. I do not see a return line back to the tank.

I will try loosening the timing cover this afternoon after I'm off work.

(quoted from post at 07:04:26 05/20/21) There is a line from the filter to the injector pump. There are four lines going up to the injectors and a return line from the injectors back to the injector pump. I do not see a return line back to the tank.

I will try loosening the timing cover this afternoon after I'm off work.

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The flow in the return line out of the top of the pump is going to the top of the injector nozzles (Tee fitting lines connecting the top of the injection nozzles), not from the injectors to the pump. There is a check valve as has been mentioned in the fitting on the pump. The check valve prevents back flow into the pump. Follow the line at the top of the injector nozzles and you will find a line, going to a fitting in the top left of the fuel tank, where excess fuel from the pump and injector nozzles return to the tank. If the line is not there it is a problem.