Hello. Just took my new motor for a drove and heard a knock. Oil pressure is fine. Its coming from the top end.

I started cracking injectors of and found that when I crack no3 the knock goes away.

Iv also noticed that there is no where near the amount of spray coming from that injector hose.
If I crack it at the pump I get a decent stream
Has anyone encountered this kinda problem.?, should I just try blow out the line ?

Iv been told it could be a fault injector staying partially open or closed