Swapping Injector Pumps on Fordson Major

[Jeff G]

We were recommended to you for this question. We bought another engine for our Major with a serial number of 1288969 with an injector pump number of SPE4A70S296 (ser# 47777B). Our existing engine serial number is 1276890 with an injector pump number of SPE4A75S647 (ser# 284034). Can we put the injector pump from the engine we just bought on our Major without any modifications? If not, can it even be done and what needs to be done? Thanks.

[JC]

Welcome to the forum, Jeff G.

The SPE4A75S pump that you have on your tractor now is for a newer engine. The SPE4A70S on the engine that you just bought is the correct one for your tractor, so bolt it on, time it, bleed it, and you're good to go. What's wrong with the SPE4A75S pump?

[Brian]

Don't forget to make sure you are on Number 1 cylinder firing stroke when you change the pump. It can be fitted 180 degrees out.



Clamp bolt is in the position shown when you are on Number 1.

[Jeff G]

We're not quite sure what the problem with the engine is. It started running rough this past summer. It's almost like one cylinder is missing. Not sure where to start as far as diagnosing what's wrong. It does start without too much trouble, though. Any suggestions? Thanks.

[Foxen]

One good bet would be to check the injectors...?

[Gman]

Welcome Jeff. You have found the right place to ask questions about Fordsons. With the help on here I get to hear that wonderful Fordson sound again. I had the same problem with my power major some years ago before she was parked until I found this site. She was running rough and by luck I could see a valve through the oil fill hole was not moving. I had a bent push rod. I was able to remove and straighten. Fixed the problem. The push rods are easy to remove. I would remove the rocker arm cover and see before removing the pump if the old pump had been working ok. Others on here can give you better advice regarding this. Anyway good luck.
Gerald

[JC]

With the engine idling, loosen one of the nuts that holds the injector line on the pump. A small amount of diesel should squirt out, and the engine should slow down. Tighten it back up, and do the same thing to the rest of them, one at a time. When you find one that doesn't cause the engine to slow down, that will be the cylinder that is giving you problems.
Keep your fingers and other body parts away when you loosen the nuts! The diesel is under very high pressure, and can go through your skin and cause body parts to be amputated.

[The Swanndri Guy]

Hi Jeff, let us know how you get on with your Major . Cheers The Swanndri Guy.

[Dandy Dave]

Welcome Aboard Matey! I,ll raise you one, and double that bet that it is most likely an injector, or a bent push rod. Some of us on this site are Fordson Crazy, and some, like me, are just Plain Nuts. And salted ones at that. Dandy Dave!

[Jeff G]

Thanks for the excellent help! We loosened each injector line one at a time and found no fuel going to cylinder 3. We changed out the injector pump, timed it up, and, all is well! We're trying to figure out what to do with the 'bad' pump. Any suggestions? We'd like to get the other engine up and running, too. Thanks again!

[The Swanndri Guy]

Jeff, good to hear that your Major is running properly,well done! With your "bad"pump you could send it to a Diesel&turbo specialist to get it overhauled, so you can put it back on your other engine.Cheers TSG.

[Dandy Dave]

Daahhhooooo. I lost the bet. Delt a poor hand. Glad to hear that you got her running proper now. Dandy Dave!

[JC]

Jeff
The #3 plunger on your old pump is probably stuck in the up position. I have freed them up before, but that's not really the right way to fix it, because some damage has probably been done. Its best to send it to a fuel injection shop, but it will be expensive.

[Jeff G]

Wanted to thank you folks for all the help. It was very cool to hear that tractor running that smooth again! Dad bought it new 50 some years ago. He was asking if you folks happen to know the average age of the folks who help via this webpage? It's pretty cool hearing from so many people from all over the world that have these. Thanks again.

[henk]

Glad he's running well now.

I guess Pedro is the youngest of us. Now who's the oldest?
I'm from '56

[Kim]

1947 for me!

[Aussie Frank]

Hi Jeff,

If you are planning to use the bad pump again make sure that you don't store it dry. Brian has mentioned a special oil that is filled into the pumps for long term storage. It is probably mentioned in the old forum but I can't seem to find the name at the moment. If you store it dry it will have 4 stuck plungers the next time you try to use it.

Regards, Frank.

P.S. I am only a 59 model, thats why I still have so much to learn.

[Foxen]

The day you stop learning is the day you die, eh? I'm a 1978 model, keen on learning

[Jeff G]

Sorry to be a bother, but we're a bit lost again. Our tractor is a bear to start since we installed the 'new' injector pump. Once it's running it runs smoothly, but seems to lack much power. We re-timed it multiple times with no change in performance. It had good power prior to the faulty injector pump issue. Any suggestions? Thanks again.

[JC]

Where do you have the timing set? It sounds like it still may be a little bit off.

[Brian]

As long as the marks line up there is no need to adjust the timing. Timing details for your engine are in the post at the head of this forum.

As the problems started after you changed the pump it is possible that this is faulty. Have you checked fuel filters in the tank, lift pump and replaced the cartridge?

You may need to get either pump checked at a diesel repair shop. Pump repairs are not something you can do yourself.

[Jeff G]

When we had our 'original' 70 series pump rebuilt years ago, we also had the injectors re-worked. Somehow we ended up with the '75' series pump. Not sure how and we didn't realize it until now. We're thinking they may not have been able to repair the original pump and just gave us the 75 series one. Were the injectors which mate up with a 75 series pump different from those used with the 70 series pumps? Maybe the gave us 75 series injectors with the 75 series pump. Now we're trying to mate a 70 series pump with 75 series injectors and perhaps that's what's causing our issue? Does that make any sense or am I full of beans? We could exchange the injectors with those from engine we removed the pump from. Thanks. Jeff

[Brian]

The injectors are interchangable throughout the range. There were different nozzles but they will work in all engines.

[JC]

As long as the marks line up there is no need to adjust the timing.

I understand what you are saying, Brian. That is what I did when I put my "eBay pump" on my Power Major a few days ago. I lined the marks up on the old pump before I took it off and and put the new pump on with the marks lined up. I didn't even look at the degree marks on the flywheel. If the claw bolt had been loosened during the pump exchange, that wouldn't work. I was thinking that maybe the claw bolt had been loosened on Jeff's engine.

[Brian]

Never thought of that JC! I got so used to changing them. I always set the marks on the flywheel before I took the pump off then everything was ready when I put the pump back on.