Car won't start an check everything I'm thinking it's the vats system need help.

What is your question?

I changed my old engine with a rebuilt one put everything in its place check for fuel,ignition,and oxygen don't what else to check all parts on the engine are new and it won't start it cranks but no start could it be my Vats system ? When I start my engine the security light stays on and it cranks but it won't start.please help thank you.