Any Injection pump specialists???

[tbrooks26]

So I have been working on this JD 4600 since back in October. It's been slow going as I'm building a house by myself (besides working full time) and have limited funds and time. So this tractor was sitting for a very long time. The injection pump was gummed up and stuck, but with time and lube and a wooden dowel, I was able to get it free. My problem is that the tractor won't shut off. The solenoid is working as it should, the plungers are rotating free and easy in the pump, and I just put all new injectors in. I've got a vid of the plungers while turning the key off/on here

It has to be something in the pump, which I know little about, except it is an inline pump on a yanmar motor. Most everyone says it must be the solenoid, but I know its working, I've tested it on the tractor and off the tractor on a separate battery. I've also tried using a hex/allen key with the solenoid removed, to engage the lever inside, but it doesn't help. I'm at a loss, and can't afford an IP rebuild. Tomorrow evening, my plan is to check the plungers again, as that video was months ago. The only other thing that I can think of is that the plungers themselves aren't sealing properly. It would be nice if the info and innerworkings of these pumps wasn't so secretive. I may try to remove the governor, to see if I can learn more or find a problem. Also it does sound like it is running on all 4 cylinders when you turn the key off. The sound doesn't really change, it just idles way down.

 

[Jerry/MT]

So I have been working on this JD 4600 since back in October. It's been slow going as I'm building a house by myself (besides working full time) and have limited funds and time. So this tractor was sitting for a very long time. The injection pump was gummed up and stuck, but with time and lube and a wooden dowel, I was able to get it free. My problem is that the tractor won't shut off. The solenoid is working as it should, the plungers are rotating free and easy in the pump, and I just put all new injectors in. I've got a vid of the plungers while turning the key off/on here

It has to be something in the pump, which I know little about, except it is an inline pump on a yanmar motor. Most everyone says it must be the solenoid, but I know its working, I've tested it on the tractor and off the tractor on a separate battery. I've also tried using a hex/allen key with the solenoid removed, to engage the lever inside, but it doesn't help. I'm at a loss, and can't afford an IP rebuild. Tomorrow evening, my plan is to check the plungers again, as that video was months ago. The only other thing that I can think of is that the plungers themselves aren't sealing properly. It would be nice if the info and innerworkings of these pumps wasn't so secretive. I may try to remove the governor, to see if I can learn more or find a problem. Also it does sound like it is running on all 4 cylinders when you turn the key off. The sound doesn't really change, it just idles way down.

The purpose of the fuel solenoid is to cut off fuel flow to the pump, thus shutting the engine down. You say the solenoid is working but you can't shut the engine off so the solenoid is not working! It is not cutting off the fuel flow.

That implies that while the electromagnet maybe good, the valve part of the shutoff is stuck in the open position and is not closing. Your solenoid is a normally closed valve that is powered open when the key is in the run or start position. It is most likely actuated by a spring to close when the solenoid is de-energized. So focus on finding out what's wrong with the solenoid valve operation.

Having reviewed your video, it appears the solenoid also does something inside the pump. Is it possible to operate the engine and observe the solenoid operation when you attempt to cut off the fuel delivery to the engine? That's the situation that's causing the issue. With the engine operatiing the fuel cut off is not cutting off the fuel.

 

[tbrooks26]

Thanks for the input Jerry, but thats what most people assume as well. In ur last paragraph, you are getting closer to the reality of the situation. The solenoid does not actuate a "valve", but actuates the control rod, which in turn rotates the plungers to control fuel flow. This video will help enlighten you to the inner workings.

Now I do not know 100% that this is exactly how my pump works, but have been told by multiple sources that the rotating of the plungers is the fuel shut off. It actually does not shut it off, but creates an outlet so that enough pressure cannot be built for fuel to reach the combustion chamber. So with the plungers rotating freely, and I believe fully, as shown in the video above, there should not be an issue. The only thing that I can think of is that there may be some blockage in the bypass section of the plungers, not allowing the fuel to fully bypass, and therefore still creating pressure to the injectors.

I was hoping before that my injectors were stuck open, because it was running rich, and that was allowing unpressurized fuel to enter the combustion chamber and allowing the tractor to continue to run. My old injectors did test bad according to JD, but it did not fix my shut-off problem. It was dark last night when I ran it, so I'm not sure if it is putting out as much smoke as before, but the knocking is definitely better, so I don't think its rich anymore. I'm gonna have a friend more familiar with diesels come by and see what he thinks. I really don't know, as this is this first diesel I've ever worked on, but this is what I have learned so far.

With the engine running, when you adjust the throttle, the plungers do rotate adjusting fuel flow. No matter the throttle position, when I turn the key off, the plungers fully rotate, and the rpms drop way down. If i turn the key back on, they return to the same position, and the engine to the same rpm. There was a time a few months ago, when I first got it running and it was cold, I had the throttle all the way down and when I turned the key off, it actually slightly raised in rpm. I know the governor has some say in the control of the plungers, but I am not sure how or if it could affect shut-off. I'm hoping someone with more IP knowledge can give some information, rather than me just tearing into it blindly.

 

[Redfieldwk]

HI I am new to this conversation and I have a problem. My injector pump failed and I need to replace it This is on a Ford 1700 2 cylinder Tractor.
I need to know how to remove old one so I can have it rebuilt. Can someone help me?

 

[jaydee325]

Thanks for the input Jerry, but thats what most people assume as well. In ur last paragraph, you are getting closer to the reality of the situation. The solenoid does not actuate a "valve", but actuates the control rod, which in turn rotates the plungers to control fuel flow. This video will help enlighten you to the inner workings.

Now I do not know 100% that this is exactly how my pump works, but have been told by multiple sources that the rotating of the plungers is the fuel shut off. It actually does not shut it off, but creates an outlet so that enough pressure cannot be built for fuel to reach the combustion chamber. So with the plungers rotating freely, and I believe fully, as shown in the video above, there should not be an issue. The only thing that I can think of is that there may be some blockage in the bypass section of the plungers, not allowing the fuel to fully bypass, and therefore still creating pressure to the injectors.

I was hoping before that my injectors were stuck open, because it was running rich, and that was allowing unpressurized fuel to enter the combustion chamber and allowing the tractor to continue to run. My old injectors did test bad according to JD, but it did not fix my shut-off problem. It was dark last night when I ran it, so I'm not sure if it is putting out as much smoke as before, but the knocking is definitely better, so I don't think its rich anymore. I'm gonna have a friend more familiar with diesels come by and see what he thinks. I really don't know, as this is this first diesel I've ever worked on, but this is what I have learned so far.

With the engine running, when you adjust the throttle, the plungers do rotate adjusting fuel flow. No matter the throttle position, when I turn the key off, the plungers fully rotate, and the rpms drop way down. If i turn the key back on, they return to the same position, and the engine to the same rpm. There was a time a few months ago, when I first got it running and it was cold, I had the throttle all the way down and when I turned the key off, it actually slightly raised in rpm. I know the governor has some say in the control of the plungers, but I am not sure how or if it could affect shut-off. I'm hoping someone with more IP knowledge can give some information, rather than me just tearing into it blindly.

What is being shown is a port and helix design injection pump. The port is through which the fuel returns to tank. This is stationary. The helix is machined into the piston. As the piston is rotated by the rack, the relationship between the helix and the port changed. This effectively affects the stroke length over which fuel is injected. At idle, the helix aligns with the port very early in the stroke, limiting the amount of fuel injected. At full fuel, the helix does not align with the port until late in the stroke. This provides maximum fuel.

To stop the engine, the solenoid through the linkage has to rotate the piston to align the helix with the port immediately so no portion of the stroke can inject fuel. The fuel then just goes back to tank. No fuel to the injectors = engine shuts down.

My guess is that the linkage is not adjusted properly to have the helix in all pistons aligned with the port to tank in the shutdown position.

 

[tbrooks26]

What is being shown is a port and helix design injection pump. The port is through which the fuel returns to tank. This is stationary. The helix is machined into the piston. As the piston is rotated by the rack, the relationship between the helix and the port changed. This effectively affects the stroke length over which fuel is injected. At idle, the helix aligns with the port very early in the stroke, limiting the amount of fuel injected. At full fuel, the helix does not align with the port until late in the stroke. This provides maximum fuel.

To stop the engine, the solenoid through the linkage has to rotate the piston to align the helix with the port immediately so no portion of the stroke can inject fuel. The fuel then just goes back to tank. No fuel to the injectors = engine shuts down.

My guess is that the linkage is not adjusted properly to have the helix in all pistons aligned with the port to tank in the shutdown position.

Thank you for the informative response. I am assuming that is how my pump works, but I can not be 100%, as I said I am new to diesels. So the linkage could have been distorted/jarred when I began working on the tractor, because all of the plungers were stuck. Sounds like a very plausible solution. I assume this linkage will be inside the governor?

 

[jaydee325]

Sorry, I'm not familiar with that pump in particular, only familiar with its basic design principles.

Your video shows the pistons being rotated by the action of the solenoid. Suggest you find where the linkage is attached to the piston rack and trace it back to the solenoid.

 

[Mysfyt]

Just a guess here, but I'm thinking your plungers are worn and/or the plunger bores are scored allowing fuel to bypass. Did I read correctly that they were froze up in the pump? How did you free them up? How is the throttle response? Is there a lag when you increase rpm?

Probably not what you want to hear, but pumps of this type are not very forgiving.

 

[tbrooks26]

Actually, I think that would create the opposite problem, and possibly cause fuel to leak by the plungers into the housing. It would not allow as much pressure to build feeding the injectors.

Yes they were frozen in the pump. I filled the pump with pb blaster and allowed it to soak for days, then I used an oak wooden dowel, shaved down to the proper size, to tap on the top of the plungers to break them loose. Throttle response seems to be fine. Someone I was talking to before said that I could probably replace the plungers myself, with the pump on the tractor, but once I got them moving freely, and had the tractor running, he didn't think it was necessary. He was no pump expert, but he did have a little knowledge of them.

 

[Jerry/MT]

Thanks for the input Jerry, but thats what most people assume as well. In ur last paragraph, you are getting closer to the reality of the situation. The solenoid does not actuate a "valve", but actuates the control rod, which in turn rotates the plungers to control fuel flow. This video will help enlighten you to the inner workings.

Now I do not know 100% that this is exactly how my pump works, but have been told by multiple sources that the rotating of the plungers is the fuel shut off. It actually does not shut it off, but creates an outlet so that enough pressure cannot be built for fuel to reach the combustion chamber. So with the plungers rotating freely, and I believe fully, as shown in the video above, there should not be an issue. The only thing that I can think of is that there may be some blockage in the bypass section of the plungers, not allowing the fuel to fully bypass, and therefore still creating pressure to the injectors.

I was hoping before that my injectors were stuck open, because it was running rich, and that was allowing unpressurized fuel to enter the combustion chamber and allowing the tractor to continue to run. My old injectors did test bad according to JD, but it did not fix my shut-off problem. It was dark last night when I ran it, so I'm not sure if it is putting out as much smoke as before, but the knocking is definitely better, so I don't think its rich anymore. I'm gonna have a friend more familiar with diesels come by and see what he thinks. I really don't know, as this is this first diesel I've ever worked on, but this is what I have learned so far.

With the engine running, when you adjust the throttle, the plungers do rotate adjusting fuel flow. No matter the throttle position, when I turn the key off, the plungers fully rotate, and the rpms drop way down. If i turn the key back on, they return to the same position, and the engine to the same rpm. There was a time a few months ago, when I first got it running and it was cold, I had the throttle all the way down and when I turned the key off, it actually slightly raised in rpm. I know the governor has some say in the control of the plungers, but I am not sure how or if it could affect shut-off. I'm hoping someone with more IP knowledge can give some information, rather than me just tearing into it blindly.

I see how this is supposed to work thanks to your videos. Apparently when the rack rotates the metering valve to the closed position, it isn't closing the metering valve (linkage problem) or the metering valve is leaking in the closed position (a wear problem). there is a poster in these forums who goes by Dieseltech. He's very knowledgeable about injection pumps and rebuilds them. You might consider asking for his help by starting another thread.

 

[jaydee325]

Below is a scan of a couple pages out of an old fuel injection text book (hope no copyright violations here!) Hopefully this will help explain my earlier description of how the port and helix (or plunger and helix) work.

Basically what is being done is fuel pressure is relieved back to tank, resulting in no pressure to the injectors which shuts the engine down.

If there was leak by in the system, that would just enhance the process of no fuel reaching the injectors.

View attachment Fuel Injection.pdf

 

[Dieseltech]

Is there a chance the plunger sleeves have "jumped teeth" at the rack? That will cause MAJOR problems with fuel delivery too. May be no choice but to tear the pump down and start over. If you want call me some evening,574 893 4172. Be glad to visit with you about the whole pump history, cause right now something does not make sense to me, and I've been repairing pumps Forty years..

 

[tbrooks26]

Is there a chance the plunger sleeves have "jumped teeth" at the rack? That will cause MAJOR problems with fuel delivery too. May be no choice but to tear the pump down and start over. If you want call me some evening,574 893 4172. Be glad to visit with you about the whole pump history, cause right now something does not make sense to me, and I've been repairing pumps Forty years..

Thanks much, I'm beginning to lose hope. I'll call in a few if thats alright.

 

[tbrooks26]

Hey man I appreciate your help, I wanted to write this to you so I didn't forget anything. I will try and give you a call about 830 tonight, if thats ok. I'm on eastern time here, not sure about you. As for history, this thing only has 630 hours on it. Somewhere between 5-10 years ago the guy broke the backhoe attachment mounts, and a few other things on the back, and it has been sitting ever since. He said it was running perfectly fine before that happened, and continued to run fine after the mounts broke, until he turned it off. I have everything else fixed except this fuel issue. At first I wasn't getting fuel to the injectors, so I checked the solenoid, which was good. From there I took the cover off the IP, and discovered the plungers were stuck. So at first I filled it with carb cleaner and let it sit for a day or two. Found out that could be bad for seals, so I flushed that and filled it with pb blaster. I let it sit for a few days, flushed and filled again and let sit for a few more days.They still wouldn't break loose on their own so then I removed the fittings and check valves from the top, and used a wittled piece of oak dowel to tap the plungers to break them free. I also had to use a hammer and screwdriver and gently tap or sometimes pry the gear fittings on the plungers to get them to rotate. I was gentle and spent quite a bit of time on this until eventually they rotated freely. Since then, it had been running, but won't shut off. I was really hoping the injectors were stuck open allowing low pressure fuel to enter the cylinders. JD said that they all tested bad, so I replaced them all, but it didn't seem to make any difference. It has been smoking pretty bad and had a knock since I first got it started. I was hoping that would clear up, but it hasn't. Of course it hasn't been run much either. Thats because the clutch is froze, I am unsure of the brakes condition, and without being able to shut the tractor off, I don't want to try and move it. I have only been running it 5-10 minutes max, and I've only done that 10-15 times. I have not done any bleeding to the system since the new injectors, which may make a difference, but it is supposed to be a self-bleeding system. Thanks again for your help, I think that is everything, I knew I'd forget half of it on the phone lol. Also I did try using the throttle and adjusting the low idle to kill the tractor as another member suggested, but it didn't work. The idle hardly went down at all actually.

 

[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

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.

 

[tbrooks26]

Just thought I would give a follow up on this. Took awhile cause I am a busy man. As of a few days ago she is up and running!! Cost me almost $1k, but its running nice and smooth, and turning off with the key! The shop said that the plungers and sleeves were in good condition also. So I didn't mess them up when I broke them free.