JD 4600 won't turn off

[tbrooks26]

As some of you know I've been working on this tractor for a little while in my spare time. Got some things fixed, got it running, but it won't turn off. I have to turn the fuel shutoff and wait for it to run dry. I talked to a guy at my local JD, who suggested a new solenoid, and said basically that was my only option other than rebuild. Well I have had the solenoid out a few times, and it seems to be working fine, and rotating the plungers properly. I have also tried rotating the plunger pinions by hand, and using an allen key with the solenoid removed, to press the lever inside. The plungers are moving freely. It has been sitting for over a week now soaking with some PB, but still no change. I'm thinking it must be something to do with how the plungers seal, to shut the fuel off. Which means it would be time for a rebuild. Maybe I can find a kit somewhere and do the top end myself. It doesn't look too hard, but it may require special tools. It would be nice to get this fixed without removing it from the tractor though. Any Ideas?

 

[davesl708]

I would agree the solenoid is not the problem. Solenoids should fail shut not open. Fuel is leaking by.

 

[tbrooks26]

I had a friend who knows a little more about diesels stop by n listen. He thinks my injectors aren't closing and its running rich. Might also be why it won't shut off?

 

[pat32rf]

Are you 100% certain that the voltage is being removed from the solenoid when you open the key switch? ALL of the voltage?

 

[tbrooks26]

I haven't put a tester on it, but removing the solenoid and using the Allen wrench in its place, or turning the plungers by hand eliminates that as the problem. Somehow fuel is still entering.

As I understand it when the plungers turn they create a bypass circuit for the fuel to return to the tank. So they are always pumping fuel. If the injectors are stuck open, then they might allow low pressure fuel to enter the cylinders. At least that's my theory, not sure if it is true

 

[tbrooks26]

Any other input on this? I'm really hoping/leaning towards the injector(s) being stuck open. I just think that after the trouble I had with the plungers being stuck, its logical the injectors could be stuck as well. Of course I have limited diesel knowledge, so I could be totally wrong. I haven't had time to work on it again. Not even sure what I should do with it, I don't want to keep running it. I know I can loosen the lines to isolate a bad injector, but I also know how dangerous high pressure diesel is. And if it is more than one injector it might not be so easy to tell. So far no signs of fuel getting into the oil.

 

[Billrog]

If the fuel solenoid is working it will shut off ...

 

[tbrooks26]

It is working, promise check this out
https://www.youtube.com/watch?v=ZusHCfOBmsg
Thats what happens just flipping the key on and off. The plungers won't rotate any farther. If not the injectors, the only other thing I can figure is seals in the IP

 

[tbrooks26]

Finally was able to get back to work on this guy. I just got some property so I've been focused on that for the past couple months. Today I went ahead and pulled the injectors. It was a pita, took most of the day. Had to tear the whole dash apart and remove the gas tank to get to them. They look pretty nasty, and took quite a bit of work with the slide hammer to get them out. Tomorrow I'll have to pick up something to soak them in. Hopefully I can get them cleaned up and working again. I guess after I get them back together, I'll take em to my dealer to let them test them before re-installing. Its my first time attempting this, but from videos I've seen, it shouldn't be too bad.

 

[Tx Jim]

I'll bet even if inj are leaking(not popping off correctly) that the injectors are not the reason engine won't stop running when key is turned to off. Engine not stopping is either faulty solenoid operation or faulty injector pump but not faulty injectors.

 

[tbrooks26]

I'll bet even if inj are leaking(not popping off correctly) that the injectors are not the reason engine won't stop running when key is turned to off. Engine not stopping is either faulty solenoid operation or faulty injector pump but not faulty injectors.

Thats what I would think too, check out my vid above. Solenoid is working, and the plungers are turning as far as they will go. As much trouble as I had getting the IP working correctly, could mean that there is something still wrong in there. It also points out how bad everything is gummed up, and I'm sure that at least one injector is stuck open. When I first started working on this thing, I put close to 9 gallons of diesel in (used a gallon or so to flush the tank out). Sure I wasted some working on the IP and bleeding and running it maybe 20 minutes altogether. When I drained the tank the other day, I got about 6 gallons back out. Seems like alot of fuel to me, and doesn't seem to be getting into the oil. It was smoking a good bit, and knocking more that it should. This is the first diesel I've ever worked on, so my knowledge is limited, but seems I probably have an injector problem either way.

My understanding of the IP, is that it is always pumping fuel, and always the same amount of fuel. The plungers turn, exposing a channel, to allow fuel to bypass back to the tank, essentially controlling throttle. Even when the plungers turn to the "off" position, they are still pumping fuel, but the amount of bypass is so large that the pressure can not over come the pop pressure of the injectors. Therefore if multiple injectors get stuck open, fuel could continue to enter, and keep the engine running (maybe lol). Without further knowledge of the internals of the IP, this seems like a feasible, logical explanation to me, but I could be way off. I found a guy online who knows a good deal about diesels and IP's, and after seeing my video, his response was 'the plungers are working perfectly, and fuel should be shutoff ' but agreed my theory may be correct. All I can do is try.

 

[tbrooks26]

Well I passed on cleaning the injectors myself, don't really have the time anyway. So I had the old lady drop them off with JD. To my surprise, they don't work on them so they shipped them off. They called me back today. They said they are all shot!:thumbdown: They told me $725 to rebuild them, or $760 for new ones Gonna start a new thread to see if anyone knows where to find some cheaper!

 

[RalphVa]

The mechanic showed me how to shut down my 1025 with the solenoid removed. He just stuck his finger into the hole where the solenoid was and pushed on a valve there.

This is one of about a half dozen problems I had with the 1025. Traded it in and got a 2025.

Ralph

 

[tbrooks26]

Thanks, but that doesn't work either. I'm really hoping new injectors are gonna fix it. Won't find out til I get some more $$$ though.

 

[skyhook]

Check out Ebay for your injectors, just google "JD 4600 fuel injectors ebay" heres a sample.....these are $30 a piece.

Ford Tractor F4860899C0010 Fuel Injector 8 5 inches Long | eBay

 

[tbrooks26]

Thanks, but I've tried that, and tried the part number on ebay and google. I haven't tried looking for the other tractors these injectors fit though, I'll give that a try this evening.

 

[Soundguy]

Thanks, but that doesn't work either. I'm really hoping new injectors are gonna fix it. Won't find out til I get some more $$$ though.

Keep hoping!, because injectors won't fix it!

You kill fuel to stop a diesel.

 

[skyhook]

Are you 100% certain that the voltage is being removed from the solenoid when you open the key switch? ALL of the voltage?

I also have to agree with this post and the one above, remove the wire that feeds the solenoid on the pump and that should kill it. If theres power to the solenoid all the time, it will not shut down. I personally don't think its the injectors either. The solenoid is where you should be trouble shooting.

 

[Egon]

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.

 

[Billrog]

If there is full power to the solenoid all the time it will burn up the wiring. You can hold your hand on the solenoid while the key is being turned on and off and you should feel it if it activates. Egon has given a much more through description than me even though I've dealt with a few fuel rod, relay and solenoid problems.