JD 4600 won't turn off

[tbrooks26]

Thanks for the replies guys, JD says the injectors are trash, so I have to replace them anyway

Assuming:
The fuel pump has four lines coming off of it. Each line goes to an individual injector. There are no electrical wires to the injectors.

There is a low pressure line from the injection pump that discharges to the fuel tank.
On the fuel line there will be fuel shut off valve , then sediment bowl then on to the manual prime pump and thru the fuel solenoid into the injection pump.

If so: if the fuel supply is closed of at the tank the engine should shut down. No fuel. If the key is turned off the fuel solinoid should close and stop engine.

So, with the key shut off and engine running close the fuel supply at the tank. The engine will run for a bit but will shut down. If that happens it takes the injectors out of the problem area and places it in the switch - solinoid control. For solenoid control it can be removed and checked with the key while connected to the wiring harness. If the solenoid still does not work remove frame wiring harness and very briefly apply 12 volts. If it then works go after back to the relays, fuses and thermistor if it has one. After that it's the switch. Remember that a faulty wiring connection or switch contact could be the problem.

the injectors may need servicing but unless they are under individual electronic control they are not your problem. If they stick open fuel should show up in the exhaust manifold and start leaking out.

So, Yes pump has four line, there is no electrical to the injectors. There are low pressure return lines on each injector. On the fuel filter itself, there is a shutoff, and other components as you listed. The engine will shut down after the shutoff is turned, but it does take a little while.

The solenoid operates correctly/the same, in or out of its location, or hooked up independently to another battery. The video in post #8 shows the injection pump when the key is being turned off/on. I was told by an expert that the solenoid rotates the plungers, and this turns the fuel off/on. He was quite stunned and stumped to see the vid of the plungers rotating, and knowing that the tractor would not turn off. You can see in the video the plungers are clearly rotating, and I might add they rotate freely and easily by hand, and they rotate the same wether the tractor is running or not.

Now this video is one that I saw that helped me understand better how it works https://www.youtube.com/watch?v=w9jMvJZwRuE

So, by looking at this, and knowing the plungers should be rotating to the full bypass position would lead me to believe my previous theory, that enough fuel is still reaching the injectors (and they are allowing it past) to keep the engine running. Either that or the bypass circuits are clogged, but if that were the case, the throttle would not operate correctly. I honestly haven't looked at the exhaust, but it was putting out some pretty black smoke when running. I have kept an eye (or nose) on the oil, and the fuel doesn't seem to be getting in there.

Thank you guys again for the input. I won't be doing anything else until I get some injectors any way, and can get the tractor back together.

 

[Egon]

Boy oh boy is there egg on my face. Thank you for even replying to my post and my apologies for wasting your time.

Your theory is perfectly plausible. After watching the video and then looking at my manual for a JD 4200 the solenoid, which a lot of us think shuts off the fuel, does no such thing. It disables the injection pump plungers.

Good results on the repair and I will bother you no more.

And now I know what makes the "clacking" sound when I turn the key.

 

[pmsmechanic]

Look in John Deere parts for the part number and google the part number. You'd be amazed at what sometimes shows up.

I was feeling generous so I did it for you.

Google john deere parts. Part number is AT110293. Google part number. Then pick who you want to buy from.

 

[tbrooks26]

Boy oh boy is there egg on my face. Thank you for even replying to my post and my apologies for wasting your time.

Your theory is perfectly plausible. After watching the video and then looking at my manual for a JD 4200 the solenoid, which a lot of us think shuts off the fuel, does no such thing. It disables the injection pump plungers.

Good results on the repair and I will bother you no more.

And now I know what makes the "clacking" sound when I turn the key.

Seriously :shocked: I haven't had anyone tell me that they thought I was right lol Even the expert I spoke to seemed very skeptical, but could give no alternatives. No egg on your face at all, from what knowledge you had, you were giving the obvious answer. I am new to diesel engines, and if not I may not have discovered how it truly works. I'm glad I had the courage to mess with the IP and learn how it works (sort of lol).

Pms, thank you as well. I have had the part number memorized for a few days, thats how I discovered it was used in other tractors, but there are not many options. I haven't tried any of the sites like machinery trader (I think it was called), as I have never dealt with any sites like that before. It seems from what I have seen in my searches, it will be over $700 no matter where.

 

[skyhook]

tbrooks26,, so your saying with the key "off" the engine still runs and you can throttle the engine normally as if it were keyed on.!!

 

[skyhook]

Another observation I noticed from post #8 video is that the inside of your pump looks pretty dirty. Looks like oil in the pump, is your oil level dropping?,,diesels will run off or feed off their engine oil if given a chance.

 

[tbrooks26]

IIRC no, the throttle has no affect with the key off. With the throttle up, when you turn the key off, it drop the rpms down to the same speed as if the throttle were all the way down. There is supposed to be oil in the pump there to lubricate it. And no, the oil level is staying consistent, I've been keeping an eye on it to ensure that diesel is not mixing with it.

 

[Egon]

IIRC no, the throttle has no affect with the key off. With the throttle up, when you turn the key off, it drop the rpms down to the same speed as if the throttle were all the way down. There is supposed to be oil in the pump there to lubricate it. And no, the oil level is staying consistent, I've been keeping an eye on it to ensure that diesel is not mixing with it.

That information is confirming the stuck injector observation.

 

[tbrooks26]

Well, I'm bummed.

First of, the guys at JD gave me an awesome deal on the injectors. They only made me pay freight for the testing of the old ones, and then they gave me an awesome deal on the new ones. I was able to take them home for less than $700 When I got them home and opened them, they didn't come with new seals, this turned out to be a major headache, as JD couldn't figure out the part# for them, but I finally got them too.

I took the evening off from working on my new house, got the new injectors in, and got the fuel tank, dash, etc all put back in. Finished up just after dark, but I had to run get some fresh fuel and give it a shot. Got it running, and it sounded better to me, couldn't see how the smoke was, but still wouldn't turn off :thumbdown: Even pulled the solenoid out, and she kept on going. After about 5 minutes the filter was almost dry and I blocked the intake and killed it.

Gonna go back after work tomorrow and check things over again, but I'm not sure what to think. Gonna take the IP cover off again, and make sure its still moving properly. Gotta try asking around some more and see if I can find someone who can give me some more info on the IP, because it has to be in there somewhere.

 

[tbrooks26]

For those interested, I finally got some more time to work on this. I found that it would seem the plungers have spun inside the pinion gears
View attachment 470514
Dieseltech informed me that it has to go on a test bench to get corrected, so I will be looking into getting that fixed, and report back if it works.