2001 Sunfire fuel pump

I have a 2001 sunfire in the past year I have had to put in 3 fuel pumps. Mechanic put first one in Jan 2010 when car would not start. 4 months later same problem car would not start mechanic replaced the fuel pump again said he thought it was bad fuel pump. 3 months later same problem car would not start. AAA got it to start by pounding on the fuel pump. In July New mechanic said it was fuel pump because it would start sometimes and not others, also sometimes would lose power when driving. He replaced fuel pump. 2 weeks later did the same thing. He then replaced the electric chasis to the fuel pump. Ran fine for 2 months now is back to not starting again. My daughter has the car 500 miles from home and her new mechanic says it is a bad fuel pump. We could not have gotten 3 bad fuel pumps in less than 10 months. What could be causing this? Obviously from reading other posts this is a problem and it keeps being diagnosed as fuel pumps when its not.