need help. rb20 just shut off while driving and now just cranks over

[slidn240sx]

aight so to start i will say that i have had the motor in and running for several months and put a little over 6000 miles with no problems.
but the other day when i was just driving (not even hard on it. not even in boost) it just shut off on me. didnt hesitate or nothing just completely shut off. i pulled over and tried to start it back up and all it does is just crank but wont start. didnt even stumble or act like it would start. i can hear the fuel pump kick on so i am assuming no spark. my buddy has a rb20 also (but havent had his actually running yet cause its still being swapped.) but i tried the CAS, ignitor, and ECU from his car and still nothing.
anyone know what could be wrong or what to try? any help is greatly appreciated. thanks

im thinking possible a ground. or maybe tire rubbed thru the harness inside the fender well.