Get the Consult program from a guy in the classifieds called whatsthegoodword. After you get this cable and software hook it up to your Z and check out and see what your ECU is seeing. Plus you can shut off each cylinder 1 by 1 in this program. This is the very first tool you should ever own when owning a Z. It tells you alot. What your TPS is set to what is the voltage of the Alternator o2 sensor readings timing and so on. Once you find the cylinder that is not firing at idle then ohm out the coil packs at .07 and the injectors out at between 10 - 14.