I just put a 4afe engine in my corolla that replaced my 4afc the first week not one tick or clunk it was great but I loan it to a mate and now my injectors r clicking? R they ment to? And my camshafts r rattling the shims r in specs how ever I am getting a rattle drone them

Injectors will click, can you get a vid of it running and upload it?

maybe someone took the cams out and didn't pre-load the scissor gears before putting them back in

Yeah I checked it out they r loose how tight r they ment to be?

one of the two scissor gears is a plit design with an internal spring. This is meant to be pre-loaded to provide an anti-backlash. With it being set up right it will rattle like crazy. I can't expain how to do it here, either get a workshop manual or take it to a mechanic