OLDSMOBILE BRAVADA FUEL PRESSURE

I Checked Fuel Pressure With Engine Not Runing Switch On. It Come Up To 62 And About 2 Sec When Pump Stoped Runing The Pressure Drops...

Changed Fuel Pump Because It Had No Pressure Now It Will Crank But No Start. I Checked The Fuel Pressure, It Has 42lbs. Needs 50. What...