Been there, man. It's super frustrating when you get everything back together and it just won’t fire up. I had a similar issue on my old tractor—spent a whole day trying to get the injection pump working, but it turned out the pump was just shot. Ended up pulling it and sending it out for a rebuild. If you’ve tried everything and it's still dead, it might be time to pull the pump and have it looked at. On a side note, when I was working on my buddy's
kubota tractors, I found some solid resources on one great site. They might have some specs that could help you figure out what’s going on. Sometimes it’s just better to take a step back and regroup.