With the pump and fuel removed, you can inspect inside the tank with a borescope. I don't want to say they are absolutely bad, but if you are replacing a fuel pump its a good possibility.
Ralph in NJ is doing the timing belt on my S4s right now. He scoped the tanks, they are ok, so I'm lucky! While its apart I am getting the a/c belt, alternator belt, water pump rebuild, water pump hose, chargecooler pump rebuild, cooling system flush, and 104 degree green dot cam wheels. I only had to buy one green dot wheel because the ex-distributor pulley on GM-EFI cars already has the green dot, so that can be moved to a cam position.
During the job Ralph called, said that the crank pulley got buggered coming off, not unusual for the age. He got one from England, not too expensive, but mentioned the supplier only has a few left, and won't be any more unless someone steps up to manufacture them. If you want to keep a spare pulley on hand, now's the time to order.