Farmtrac 45 running on 2 cylinders

[Peaches04]

Hi guys, I have a 2002 Farmtrac peice of junk 45 and it started running on 2 cylinders the other day. I was unhitching a spreader and it was running fine before and as soon as I throttled up to move away it started missing a puffing white smoke. It tried to run on 3 every now and then, but just wouldn't come back completely. The prefilter is clean and I cracked the lines going to the injectors and it's the middle cylinder that's giving me the problem. It's shooting fuel out but not at the same pressure as the other 2, it kind of just spits and bubbles. I have taken the injector out and got it tested and it seems fine so that's not the problem. And for some strange reason it takes a lot longer now for the tractor to cut off, I don't know if there's any relation but I figured It might help the troubleshooting. Any help is appreciated, thank you.