1991 acura 1.8l timing belt vibration



I have a 91 acura integra it runs great but the timing belt vibrates and it drives me crazy. it does not effect performance at all. I have replaced the belt, waterpump and tensioner and still have this issue. I know they do vibrate some but this is more than I have heard on other vehicles. it vibrates from the front cam pully down to the crank. any ideas what it could be?