fuel pump will not shut off
Most probably your fuel pump reply has stuck/ failed. Time for a replacement.
I know that it's too late to answer your question but it may help someone else. I had the same problem. I discovered that the fuel relay was not functioning properly. This really surprised me because the relay was new. I actually just stuck my old relay back in. My original problem was a bad fuel pump. I purchased the new relay because I really was hoping that it would solve my problem but unfortunately it didn't.
Search Oldsmobile Cutlass Supreme Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Oldsmobile Cutlass Supreme Experts