Vibration or pulsing is usually air in the valve. If the CSV is mounted horizontally, the black plug in the top of the cover can be loosened to let the air out. If the CSV is mounted vertically it is much harder to get the air out. You will need to loosen the top two bolts on the cover and burp the air out.
Pulsing can also be caused by the pressure tank being too far from the CSV3B. You don't want any distance or elbows between the CSV3B and the tee to the pressure tank. There only needs to be a short nipple between the CSV3B and the 2" tee that goes to the pressure tank. Then you want to bush down from 2" to 1 1/4" or 1", depending of the tank inlet size. Do not start with 2" then bottleneck down to 1 1/4 before going into the tank. Then just before going into the tank you need a 1' or 1 1/4" tee where the pressure switch should be plumbed too. Right air pressure in the tank is also important.
You didn't say what horsepower the 85 GPM pump is? If it is a 5 or 7.5HP it will be fine. But if it is a 10-15 or larger it may build more than the 125 PSI differential pressure, which can also make the valve pulse. You can put a gauge on the inlet side of the CSV in place of one of those little black plugs, then you could tell if the pump can make more than 175 PSI backpressure, which is the max a CSV3B can take without pulsing.
