Will not stay running

I just picked up this truck and it was running before it was parked about a year ago. When I put a fresh battery in it, the security light stayed on and the truck would start and immediately shut off. Checked fuel pressure and it would struggle to get to 20 psi. I changed the fuel pump and filter and rechecked pressure. Now it goes up to 60 psi and holds at 55 psi. Same thing happens. Was thinking it had to do with the VATS, I put in a bypass and changed the module and ignition tumbler, did the relearn procedure and still, it starts and shuts off. Spray starting fluid in the throttle body and it runs on the starting fluid. So it was determined that the VATS wasn’t the issue. Any help would be greatly appreciated.