I have a 1997 Honda Civic Hx that i bought, the owner said that it has a knock and was sure it was rod knock. i was ready for a project so i bought the car for $600... first thing i did was checked the main and rod bearing and both where worn but none where spun. then i took the head off and the pistons where in bad shape with gouges out of them and melted over the rings so i figured that was causing the knock so i replaced all 4 pistons, honed out the cylinders and replaced the main and rod bearing but when i started it back up it still seemed to have the same sound pulse now it has problems between 1500 and 2000 rpm i have attached a mp3 of what it sounds like... is this normal valve noise or is something wrong also why is it having problems at 1500 rpm any help would be greatly appreciated

 

Is the idle bouncing as if its a IAC issue?