I'm having the same problem with my S13 KA24E. Same exact symptoms. Maybe we have the same problem... You removed your EGR right? Because that's what I think mine is but if you removed yours that rules that out. My intake is manifold coated in black and my injectors seem like their dumping. Tried my new aermotive FPR and everything. The only thing I can think now is either EGR, Timing for some reason (like CAS sensor is messed up on the distributor or the chain is skipping but it doesn't look like there is any damage when I open my valve cover), or a valve cover leak somewhere. And everytime I check my spark plugs I'm running rich across the whole block not just one cylinder. And my compression is near perfect. So if you figure yours out that would be great
LoL. My head is making a ticking sound too. So I think it's the chain but the only thing I removed off mine is the top guide unless the other two snapped off.