help me please! i have a 1993 rx7, i bought the car with an incomplete motor. recently i purchased a JDM 13b, changed plugs and wires brand new. well when i first installed the motor it started just fine and idled just fine. a week later i tried starting it again, and it was very hard to start and when it finally started it ran very rough like it was on one rotor. a week later i tried starting it again and it was hard to start but ran fine. so here is my noob question, this box came with my jdm motor, i could not find where it plugs in, i have no idea what it is, if its needed, and if it is the main reason as to why my car wont start easy? please help me!!!