Cranking but will not start after fuel pump replacement

I just got my mechanic to do a fuel pump replacement. He tested the pressure and all the fuses and relays and decided it needed a new fuel pump. After the job was done I drove around, and it started up fine all day. The next morning went to start the truck and it wouldn't start. It would crank and wanted to run but it wouldn't. Any ideas? The shop is closed for the weekend and wanted to see if it was something I could fix before Monday. Thank you