i had a problem with my z31 turbo and i couldnt figure it out for almost a year, i wasnt getting spark and i tried everything and i was about to get an aftermarket ignition for it, but i did some lookin around online and found out that the crank angle sensor is inside of the distributor and its just a disk with slots that is read by a sensor, but the sensor had gone bad on mine and therefore i got no spark, i replaced the distributor and voila, it fired right up, so if anyone isnt getting spark on they're z31 and cant figure out why, then it is something to check.