Fuel Pump Relay
I have an 88 2.8L Century and my fuel pump relay is on the passenger side of the engine bay in the front , by the evap canister. It's the one w/ a fuse holder attached to it. I don't know if it would be the same on a 3300 car.
Search Buick Century Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Buick Century Experts