Subject vehicle is a 73 fj40 with 78 distributor, igniter-type. Problem: vehicle shut down yesterday, then would start back up with key in start position, but die when key was released to Run. Replaced the "igniter" coil with a new "external resistor" coil, and it runs fine. I figured bad coil, so when I got home I put in a spare igniter coil, same symptoms as before. Installed a used resistor coil, ran fine again. Voltage while running was 5 volts at the plus terminal of the coil. Additional symptom: checked fuses when the first incident occurred, the second from the bottom was HOT but intact. My thoughts: could there be an impedence problem in the fuse block that's reducing primary voltage to the coil? What should the voltage be, at the plus terminal, 73(resistor) vs 78 (igniter)? I'm thinking the 78 coil wants 12 volts, and when the voltage dropped below six it could no longer function. Also the resistor coil should get around 8 volts, I'm thinking, and thus might have a lower threshold of failure. I'm thinking i need to clean or replace the fuse box, and that the proper (igniter) coil would then work. Tht's a lot thinking. I tired :-\ What do you mud gurus think?