VTEC not working.. help??/?

I have a 89 CRX Hf with a D16z6 SOHC from a 92 Si... I have the ECU from it and everything but it just doesn't kick in or work at all... someone told me I should pull the engine codes then it will tell me whats wrong.. well im thinking, what if it was never hooked up? How can I tell if there is something missing like the VTEC solenoid or a wire not hooked up? please help...