Van won't start after installing new computer and censors

My problem in the past with a computer swap was, as described online, the computer runs the fuel pump. But, the vehicle has to run 10 seconds to sync the computer with the vehicle. the vehicle can not run 10 seconds to sync the computer because the computer is not synced to run the fuel pump. I have been told to take the vehicle to a chevy dealer and they will "blast" ( i think that was the word) the computer to sync it to the vehicle. Call your local chevy dealer and ask. My van has set for 7 years and I know it is junk, or I would have done that, and then I would know if would work. Good luck with your project.