Engine acting wierd?

[Garrettohio]

To start out the Kubota ran fine with no smoking but had loud upper engine knock.so I replaced the injectors then started smoking.so I took them out and put the old ones back in.and it is still smoking bad.so i did the loosening injector lines.there was a change in number three and two cylinders.but on first cylinder nothing.so I figure this cylinder isn't firing.any idea why it did before injector change but not now? Don't make sense I put the old injectors back in and was ok before.

 

[damn1981]

No compression rings or piston went boom boom