2006 Hummer H3 • 85,000 miles

My car will not start it will crank and all the lights come on and every thing else works. I took it to the mechanic and they changed the relay switch and the fuel pump. After I left 2 weeks later it did the same thing so I put another fuel pump in it. And again 1 week later it fdid it again. I have changed the pump 3 different times but nothing seems to work it still will not start. It will crank and try to start but will not start.
November 14, 2012.

Make sure you are getting a good spark to the engine. Also, make sure the fuel pressure is within spec. If both are good, check fuel injectors to make sure they are getting power and working.

Every time I put a fuel pump in the pressure is 60 but a week later or so later when it won't start again I take it back to the mechanic they check the pump again and the pressure is only 20 pounds. Like I said I've some this 3 different times and the same thing keeps happening. It starts out good but then a week or so later it won't start and I have to get it towed and this is getting really expensive.

Nov 14, 2012.
Is it possible that they got a cheap pump that is no good? I realize you had 3 of them, but maybe a different brand wouldn't let you down.