Fordson won't "idle down"

Hi All,

Another question about my Fordson-- (Can you tell its getting heavy use?)

Throttle works well under load (e.g set a position and stays) BUT under no load, it is now very slow to idle down, or won't idle down, even with throttle at min. setting.

If i load her at all, will immediately idle down. (or otherwise reduce RPM's, via air intake restriction etc).

Doesn't appear to be seeking, just not returning to idle very quickly (or at all).

Thoughts?

Thanks all!

PS Found a Fordson Power Major Backhoe in my area for sale-- was this an original offering, or perhaps something put on aftermarket?

In those years, Sherman Brothers had the concession to make attachments for
Fordson tractors. At least some backhoes and loaders were built. My loader
was a Sherman built by Johnson Hydraulics in Minneapolis under contract.
The tractor did have a backhoe, but I didn't want it, and I don't remember if
it had a builder's plate on it.

As you know the throttle lever does not connect to the injection pump to control revs, this is done by reduced air pressure in the
manifold via two pipes to the governor diaphragm on the injection pump. This was a normal system on most English tractor of that
era.
Faults to look for are leaks in the air cleaner to manifold pipe. (this can also cause excessive revs and a worn out engine if not
sorted).

Sticking or loose throttle plate in the manifold.

The two governor pipes leaking. There was also a change in the pipes back in the day, there was one small and one large, if they
have been put back in the wrong place they could give your problem. A later modification was to replace the small one with another
large so both pipes were the same.

Governor diaphragm cracked or leaking.It is not a bad job but you need to take your time.

Rack in the injection pump sticking. Two things here, thoroughly clean around the side plate on the pump and take it off. It must
be very clean before you do this as the slightest piece of small grit could damage the pump. Lubricate the pumping elements and
the rack with Automatic Transmission Fluid and work the rack backwards and forward with a screw driver. It should spring back
under spring pressure.

Add a quart (two pints) of Automatic Transmission Fluid to a tank full of diesel. This will clean and lubricate the whole system.

Did you get your clutch sorted? What was the problem?

Picture of the inside of a pump showing the rack and pumping elements.

Hey majorman,

Thanks for the details, suggestions, and thoughts!

I will give it a look this weekend. Have been on the road traveling for work.

The local tractor folks said they would split the unit and take a look at the clutch. Will I have done a some point, I think one of the fingers/springs that returns the clutch is culprit after a lot more troubleshooting (sometimes when I lift the clutch petal up slowly, it doesn't engage at all, a faster lift, engages with out slip).

For now, I am working around it, but yes, need to get back to the shop.

will take a look at the air intake and pump this weekend.

Go well

Just had this on my power major, changed the vacuum diaphragm and fixed it. Had a tear in it, be careful as the more it tears the higher it
will rev ungoveroned. Got mine off ebay , think it was about $40. When you take the snap ring out of cup be careful as the spring will fly
out if you dont have a hold on it, also the metal ring is offset , make sure to notice what way it fits. when refitting the cup to pump , be
sure the groove in the shaft is locked into the 'C" shaped piece on the controll rail in the pump, i had to twist mine a little to lock it
in. If you need a copy of the manual detail i can try to take a picture of the page and post it.

I've ordered a new diaphragm for the throttle and will try putting that in when it comes; Hopefully that corrects the rev issue. I didn't see any issues with the intake pipes from air cleaner.

Ill check the rest of the system then if the diaphragm isn't visibly worn.

Any other thoughts on that backhoe set up I mentioned? I was thinking of going to take a look this week. Apparently runs well, used lightly. Backhoe needs one of the cylinders rebuilt-- is that a big job?

Thanks everyone!

Eben