Oldsmobile/Buick Repair: Fuel Pump, fuel pump relay, gasoline tank

Question
Happy Labor Day Tom,  I have a 1990 Buick Century Custom 3.3. The other day my car stopped running like I ran out of gas. I called a friend and he knocked on the fuel tank with his fist and the car started right up. I drove the car about 5 miles and it quit again. I banged on the fuel tank again and it started. Do you think the fuel pump is bad or is there another issue that could be causing this to happen?  Does this car have a fuel pump relay and if so where could I find it?  I had the fuel pump and screen replaced about 5 years ago with an AC Delco brand. I don't think the relay is bad if it has one unless it is in the gasoline tank.  I have ordered another AC Delco pump and screen from advanceautoparts.com just in case this is the problem. Is there anything else in the gas tank that could cause this and if so how do I check it? I thought of checking with you before a friend puts the new pump in to be sure if this is the problem.  Thank you for your expert advice.
Stephen

Answer
HI STEPHEN,HAPPY LABOR DAY TO YOU SIR.. ANYTIME YOU CAN HIT THE GAS TANK AND THE ENGINE FIRES AFTER THAT THE FUEL PUMP IS BAD. IT BOUNCES THE PUMP MOTOR ARMATURE ENOUGH TO GET IT IN A DIFFERENT LOCATION AND THEN THE PUMP IS OVER THE DEAD SPOT.THE PUMP IS JUST FAILING.....THERE IS A FUEL PUMP RELAY BUT IT IS IN THE MAIN FUSE BOX UNDER THE HOOD..BUT THIS IS NOT YOUR PROBLEM. THERE IS NOTHING ELSE IN YOUR TANK THAT COULD CAUSE THIS...REPLACE THE PUMP AND YOU CAN FEEL GOOD ABOUT DOING SO...GOOD LUCK TO YOU AND IF YOU NEED MORE INFO PLEASE GET BACK TO ME,,,,TOM..