2002 chevy silverado starts right up but then dies right away starts right up again but dies

By what your stating, that it starts and dies every time, It seems to be fuel related. You need to perform a fuel pressure check. You will need a pressure tester, one that would at least be able to read pressure to a maximum of 150 lbs of pressure. Although you really only need about 50-60 pounds of pressure to maintain proper fuel injector operation. There is a test port located on the fuel rail where you would conect the pressure tester. The test port is usually located on the drivers side of the engine near the rear section coming up from the firewall. Unscrew the pressure port cap if its still there and connect your tester. But also keep in mind you may have fuel pressure of some sort in the rail so be careful. While the tester is screwed to the test port you want to cycle the ignition key on and read pressure, you may want to repeat this several times. You must have at least 50 pounds of pressure, if so it should start. If you are losing pressure while your maintaining a visual check on the tester it could also be a faulty pressure regulator/fuel pump or even a rubber hose connection inside the fuel tank that connects the fuel pump to the fuel line. If you have any questions Im here to help. Thanks for using FIXYA