OK I've finally finished with my engine and it runs perfect but it takes about 5 seconds to crank and actually start. When I started it the check engine light came on, i plugged a code reader in and it gave me P1391 code. So i clicked erase on the code reader and its gone. Will this error come back and if so how do i fix it?

 

Start by checking the wiring and connectors for the cam and crank sensors, that code means one of them is intermittent.