Car will not stay running

03 saturn vue 62000 mi 4 cyl. My inital purpose was to change spark plugs. I thought I was taking the plugs out, instead I had taken out the fuel rail and the injectors. I bought a haynes and found the correct area for the plugs. Plugs were replaced. I changed out the old o rings from the injectors. Like the book had stated. Replaced everything. My wife stared the car. No gas leaks anywhere. The car will not stay running. It will crank and stay running for about 2 seconds but then it dies. There is a schrader valve on the fuel line. Should find a air gauge that will adapt to this valve and put some air in the lines and how much? Im puzzled as to why it will not stay running. Thanks for your help