ok so today i installed my zc and hooked everthing up. i go to start it and it starts on and off shaking and then stalls. we figure the distributor to be the problem, so we take it off and clean the points and the contacts and swap the coil from my d-series. put it back in and wire it up and go to start it and it starts but struggles. so i narrow it down to the fuel filter which we decided to use the one that came with the engine (jdm cuz it had jap writing on it). we take it off and the gas inside it is all discoloured so we put the one from my d-series on and starts up but still shakes so we rev it abit... at the most we went to 6000 rpm and it clears up, but then rite after it clears up it starts making a knocking type sound from the engine. the engine runs fine now and idles perfect, everything is fine except for the knocking noise. heres things i did to the engine/trans before i put it in: installed my crx si flywheel with a new clutch, replaced throw out bearing, swapped my crx oil pan cuz the zc one was dented, replaced oil pan gasket, installed new spark plugs, ported out my exhaust manifold to match the zc. my friend is an anprentess mechanic and said he cant figure it out cuz the engine idles pefect, but it makes a knocking sound and there are no codes. he said it sounds like theres something loose inside or something. i'm getting really fustrated and need your help, is this engine fucked or can anyone tell me whats wrong. i've been without a car now for a month adn i'm getting really fustrated.