I took voltage readings at the "+" side of the coil with both ECU's. (A) is the first ECU that was not showing any spark at the cap and (B) is the known good ECU. ECU (A) is now showing a VERY minute spark and ECU (B) shows a massive spark that shoots down the length of my screw driver.
ECU# Run @ Coil Crank @ Coil
A 11.2v 10.1v (non ballast ECU)
B 8.0v 8.0v (ballast ECU)

Even though ECU (A) showed 10.1v at the "+" side of the coil, the spark was very light @ crank. Even though ECU (B) showed 8.0v at the "+" side of the coil @ crank, the spark was massive.
I now have ECU (B) hooked up and I have no doubt that due to the strength of the spark that it would have no problem starting.
Does this still indicate that ECU (A) is faulty?

Note: I also checked the ground at the mounting bolts of the ECU and the mounting bolts of the ECU mount bracket and they all four showed battery voltage when the positive side of the lead was on the battery.

Note: I have read where there might be a GM HEI unit inside of this ECU. If this is true, I have also read that it takes at least 11.0v to get one to supply enough power for the START mode. I show only 10.1v at the coil during cranking. But this doesn't make sense. This no start issue started on Sunday morning when the car sat for four days and it started just fine. Then after the second half hour drive the car sat for 10-15 minutes and then the no start issue was found. This was the exact same situation that happened about two weeks ago but then the no start issue just went away.

Thanks