ive been helping a buddy install a fast xfi system, and every things works great except, while idling the injectors will at random just cut off causiing the car to die. some times it will sit at idle for 5 minutes then cut off or maybe 20 minutes, each time its different . any idea what may cause this issue? when it runs it runs great

Look at a data log and see if you see any crank/cam sensor issues.

Also check to ensure your not having an issue with the 12V feed...the ECU is just controlling the ground side.

there didnt seem to be a issue with the cam/crank sensors, we will trace the 12v and try that

Is it fixed? What was the problem?

Ron

Wrong power wire coming from the xfi box, works great now