The Fordson Tractor Pages Forum

I purchase a Fordson major Diesel last month, the person I purchased it from had changed the oils and a check on the tractor and said it was in good shape for it's age. Ran good but has some oil leaks around the rear wheels and the left brake is stuck. I got it home and pressure washed the tractor and I was going to change out the original fuel filter with a NAPA filter with water separator but I would need to alter the injector supply lines so I have not done that. I removed a secondary in line fuel filter that was dirty (Platic and semi transparent filter) but I did not open the original fuel filter (Hope it is still in there) and check it out now that I think about it. Anyway, I did find that the person had forgot to fill the front gearbox with oil. (Took 4 gallons to get to the full mark)

After the cleaning I used the tractor for about a half hour and it ran great. Today I was goingto use it and it started right up but was running fast and blowing black smoke. I worked the fuel accelerator and I could speed it up but I could not slow it down below the fast run that it started with. I pulled the fuel shut off and nothing changed. I climbed down and looked over the injector for anything out of the ordinary and all look fine (Not sure about how the excess fuel button works and at the time I was not aware of it). The tractor was starting to heat up so I shut off the fuel line from the tank hoping it would shut down, it did not. (The shut off does not completely close but should not have leaked enough to keep it running)

I then wrapped some heavy plastic around the air supply and after about 4 minutes it did shut down.

Anyone have an idea as to what I should look for?

I can not imagine there being enough oil leak around the valves or crank case mist to cause this.

It sounds to me like a fuel pump issue. Even if the cold start button is on, the 'pull to stop ' mechanism should still work. Did the stop work before? Lets see some pictures of the old beast

Does sound like a pump problem. Check the two metal pipes from the intake manifold to the pump to make sure there are no holes in them. Then remove the cap that they go into on the pump and check that the rubber diaphragm in there does not have a split in it.

What is odd is that everything worked fine when I parked it. Throttle, fuel shut off etc. I'm headed out now to see if I can figure it out. I read a lot of post last night and so I have things to look for. I'll keep you posted and take a few pictures.

No pictures yet but I did pull the vacuum lines and they are solid with no holes. The bellow does not appear to have any cracks or holes. there was a little rust from water at the bottom but I do not see that it caused any problems and it clean up nicely. I'm now researching how the small rod and spring go back in. (they popped out when the bellow let loose so I did not get a chance to see how they were installed)

I'm not sure what is supposed to move and / or how easliy. The devise that the bellow attaches to does not want to move by hand or when I actuate the throttle lever.

I disconnected the puller from the fuel shut off and when I move the fuel shut off I dod not feel anything else moving. I pulled on what I assume isthe Exess fuel lever and it pulled out a little one time, other then that when you pull on it, it does not move much. I assume I can take that end off as well without risk of damage to the injector pump.

thanks for any and all help. Back to research and trying to fix my problem.

Darrell

take side plate off injector pump you will probably find rack has partially stuck. Apply penetrating fluid and make sure it works back and forth freely, the rack operates on the 4 injector feeds, they move in a rotary motion to alter the fuelling if I remember rightly. I have had these stick before and then the engine wont shut off even when the top is pulled.

If you remove the cover, check the bronze bearing bush between the that space and the vacuum space. It could be worn and the rack will lower at one end.

Agree with Roadless 63, sticking rack if the diaphragm is not moving anything. The rack should move freely against a spring but if it has stuck at full throttle you have found your problem.

I put the diaphram cover back on and no surprise nothing changed. I did get the excess fuel button free'd up but I can not take that cover off since one of the screw slots is flared out. Even a hollow ground screw driver will not free it up.

the brass bushing that the metering rod is in is flared on one edge which I thought was strange, not sure what could cause that.

I assume by the comments that I should be able to move the rack back and forth and the bushing refered to below holds the rack. some of the threads I've read were emphatic that you do not remove the side cover and to take it to a shop. Since I don't like to take things to a shop and usually can fix them myself I will remove the cover and take a look.

Note: the throttle will move the rack enough to speed it up, just not the other direction to slow it down.

Problem solved. I pulled the side cover off and found that the rack was stuck with rust particles on the shaft at the back end by the fuel shut off. I managed to get the stripped screw out that holds the fuel shut off assymbly and pulled that apart.
I then cleaned and polished the shaft, put some light grease on it. I then re-assymbled it all back together after making sure the rack moved freely and cut a new gasket. The tractor is now running great and shuts off as it is supposed to. (Learned a lot about the simms injector pump as well.)

Thanks Brian and Roadless63 for your help.

Darrell

Glad you found it.
You mean this:

That's the shaft, I did not do a rebuild and replace end of the shaft, just used Emery cloth to clean and polish. It still has a few small pits in the shaft but slides nice and has limited signs of wear.

Hi there,
I am having this exact problem with a Super major I hadn't started in a few years. I opened the front plate of the Injector pump (the plate with simms marked on it) and noticed that tha rack wouldn't move. I applied loads of wd 40. It has improved it but it still doesn't move using the shutdown pull button.
When you say you opened the side plate, is this the left hand side of the injection pump by the shutoff device?
If I get the rack moving properly this should be all that is needed to stop the tractor?
Thanks in advance.
Chris.

corkguy30,

Remove the cover on the cold start/stop device and remove the device, Remove the vacuum on the right-hand of the pump. If the rack is not moving freely try to find out if it is stuck on the left or right-hand or on the plungers.
corkguy30,
Work in a clean environment and keep the pump covered with a clean peace of cotton.

I abandoned this last year as I couldn't get it working. However having read up more on it I decided to tackle the job again. I can conform that the stop lever moves the rack in one direction and that the throttle lever moves the rack in the opposite direction. However the throttle lever doesn't move it back in the opposite direction. The plungers are working fine also. I just don't understand by looking at the inside of the injection pump how the throttle is supposed to move the rack back in the opposite direction. Can anyone enlighten me please?

[imghttp://dl.dropbox.com/u/45245665/2012-08-12%2013.24.51.jpg][/img]

corkguy30

Can't help you there. You have a mechanical Minimec pump. I have not work on those before.