Case/DB 1690 problem

I have a Case/David Brown 1690 that was handed down to us 3 years ago by my father in law. I use it mainly to maintain our 3/4 mile long gravel drive that us and 4 neighbors live on. All the rain we had over the last week caused a large area to wash out and I had a little time just before dark. I went out hit the starter and it fired right off, but then the rpms went wild. It shot up to about 2500 rpms and I had no control with the throttle. I pulled the kill switch and nothing. It would not die. The rpms slowly came down but I still could not kill it. At that point I dropped the bucket and put it in 3rd gear and stalled it out while pulling the kill switch. Checked all of the throttle linage and that appeared to be ok. Restarted it and it did not run away so bad this time. I headed down our lane running about 1100 rpms. I could not adjust it either way. I got one bucket of gravel and when I put the clutch in to dump it the rpms went wild again up to almost 3000. I killed it the same way as before. This time it would not restart. No puff of smoke or anything. The engine turns over just fine but acts like it is getting no fuel. I have never experienced anything like this. Do I have a pump problem or is it something much worse? Thank you for any help.

I vote injector pump needs to be overhauled.

First suspect is a stuck fuelracket in the injectionpump.
Remove the cover on the side of the injectionpump, see if the racket moves freely side tot side. The injectionpump has a oilreservoir wich is often forgotten, check if there's sufficient oil.

Thats what I was thinking also. All my other tractors are of late 40s early 50s gas tractors. Have never dealt with a pump before. About how far should i be prepared to bend over to pay for this repair?

If the pump is way over full with fuel/oil/water mixture they will act very wild also. An oil change on the pump, and making sure the rack is free would be a good place to start, minimal cost and time.

Best guess, a pump rebuild is going to run $600 to 1000.

Back when diesel cars were in vogue, I had a customer with that same complaint on a diesel Rabbit. Seems one of those quickie oil-change places had just done their thing on it, and the inexperienced kid just put 5 quarts in it like everything else. Engine oil was blowing out the breather into the air cleaner housing and the diesel was perfectly happy to burn it--and of course, no throttle plate, and turning off the key did nothing. Drained the oil down to a reasonable level and it's fixed. It's still a POS, of course, but it quit over-revving for no apparent reason.