1973 Scamp won't start in start only in run. With a Twist....

So let me restate this and ask a specific question. We have 10.5 volts at the coil during ign2. We have 6 volts at the coil during ign1. It won't start When cranking until you let go of the key switch back to run. Question is what controls the other side of the coil during crank and run? Is pin 2 of the ECU in play for both ign1 and ign2?