4 pin ECU doesn't work. Old 5 pin does.

Today I decided to mess with it a little. Cranked right up in the old 5 pin ECU configuration. No go with a new 4 pin. So I had read that maybe if the distributor wires (ECU pins 4 &5) were crossed, an old ECU would fire the coil, but not a new one because of the difference in the waveform. Sort of like a generator that puts out a square wave instead of a true sinewave. OK for a toaster, not for a TV. Anyway swapped the wires with no change. Swapped everthing back and it fired right up.

Laughed and scratched my head..........
Checked voltages with old ECU. 10.5 coil + and 2 volts at coil -
Swapped a 4 pin ecu in got 11 coil + and 0 at coil -
Starting to suspect the old ecu connector is not making contact on pin 2 with these new China ecu's.

Think I'll try a bench test setup like @67Dart273 recommends.