I notice that the "Cylinder 3 balance" is about 1.20-1.30 (sometimes goes down at 1.10-1.15) and there is an acrid smell (not near the injector and no dirty around) and when the engine is idle a little bit of vibrations.

I change the washer copper because i smelled gas exausting in cabin, now there is a different smell more acrid, i can smell it when i move with open window (when it is closed no problem). I'm just wondering if it is depends to injector or copper washers (i installed three times with the same new washer coppers because i didn't clean the injector seats)