Please help me ! 1997 GMC Truck will now not start

1997 GMC K1500 4x4 auto. X.C. 25000 ks. Last friday my fuel pump died I was positive it was the pump as I could no longer hear it. I chaged the pump and the truck ran bad really poorly. I took it to Candain Tire had the Fuel Pressure Checked an it was very low so I exchanged the pump put in another. Truck ran great for 2 days yseterday while driveing down the highway I tried to make a pass and the the truck reved but gave no power. A little later I had a hard time starting it. It took a while but fired and when it did it spit and sputtered a bit. Took while to start this morning then a little later I could not get it to start again. I hear the pump going. Turns strong before I killed the battery. But just no fire. Yes I changed the filter as well checked for loose connection where I hooked up the pump all is well. I am confused what are the odds of getting tow brand new bad fuel pumps or what else may it be. Any help will be greatly apriciated. IF I find this site usefull I will crtanly not be shy of making a donation. Thank You Very Much