wire it thought the stock system.when you turn the key on the fuel pump runs for a few seconds untill fuel pressure is gained. i think it's like 3 seconds or something. but it also sends a electrical signal to your coil pack or distibitor to start firing,and it tells the injectors to start there duty cycle....i-e just hooke it into the start wire under the dash that is in the back of your switch there for it's the same as turning the key