Did you check for a blown fuse for the ECU? Check them ALL with a test light, ignition on. should light on each side of the fuses. If you have a stick shift, the clutch master sometimes leaks and the brake fluid corrodes the fuse box. You might get a wiring diagram of the ECM and verify that there is power and ground at the ECM itself. Also verify that the ignition pickup coil pulse is getting to the ECM connector.

You may have to try a temporary "Nutter Bypass" to see if the engine has spark. If so, then it may be the ECM or the wiring to it.

If I remember correctly, there's a diode box in the ECM/engine harness, but I can't say for sure if it's for the igniion control or the carb mixture control side of the ECM. Inside the box is a set of diodes that sometimes gets corroded. The box is about 2" long, 1-1/4" wide, by 1/2" deep and taped to the engine harness near the valve cover. There's a small circuit board inside that can pull out for inspection and cleaning.

Per your question on the other post, The ground goes through the pickup plate itself, the ground screw is the pickup plate mounting screw. The ground path is then through the pivot on the advance plate, thus the possibly poor ground.

If you decide that the ECM is bad, I may have a good one. I just need the number off it to see if I do. It's mounted under the dash near the glove box.