Well, I hope it is my injectors! lol! no, i am pretty sure my injectors are clicking, or one is clicking real loud. i just changed my intake manifold from a stock p30 to a s2. it didnt click before now all of a sudden, this tick, tick, tick sound appeared. i adjusted my valves about 2000 miles ago, so i doubt it is that. my valve train is perfect as far as i can tell; i disassembled it before i put the head back on before i adjusted the valves. it idles perfectly, i feel no hesitation when accelerating.
it sounds like someone is shaking the shit out of the pcv valve, to tell you all the truth; it has that same sound. oh, and it only tick, tick, ticks rapidly at 1100-1800 rpms.