Q: Why does my car keep dying on me?

Started as some engine skips, then the car began to cut off while driving.took it to auto zone so read the codes, which were a bunch of random misfires.I replaced intake manifold and valve cover gaskets for possible vacuum leak, didn't work. Car began to not even turn over however the starter turns the motor. I then replaced all spark plugs and coil packs, with the same result, no start. I found a bad ground connection to the valve cover and fixed that, the car began to run with starting fluid but wouldn't pick up gas. I replaced the fuel pump and filter and car would then crank up and turn over but die after 3 seconds. I then straight wired the fuel pump to a fuse and the car cranked and idled for about 10 minutes, but when i proceeded to test drive it and put it in gear, it began to choke and die before I could leave the driveway and now it will only run for 3 seconds and die. I wanted to get a second opinion on a possible PCM issue

My car has 78000 miles.
My car has an automatic transmission.