I've had this 71 datsun 240z for a few weeks. one day it just stopped running(it was a barn find btw). I checked the electronics. they looked pretty good. I replaced the plug wires, the sparkplugs, the condenser, the distributor, the points adn the coil( i routed a wire around the ballast resistor because the new coil produces sufficient ohms). after all this still no spark. I've started testing continuity and so far its turned out good but i still dont know where to put the ends of the ammeter thing when testing the tach to where the blue/white wire leaves the cabin. The compression is good in the engine and sufficient fuel. so i'm really at a loss as to what to do. any suggestions as to whats wrong?