d15b vtec problem & idle problem

i have a jdm d15b swapped into my 97 civic hb, it's wired obd-II i want to know why vtec doenst kick in and the car cuts off at 6,000 rpm. my car idles at 1,000 when i start the car but when i stop at a red light or at a complete stop the cars stalls so anyone with info please reply