OOPS!! HERE IS A CLUE, Steve, post 63. You say after it stalled, Coil -ve 11.8 V
Coil NEG V should be LOW, the lower the better, with proper voltage on the coil+. Coil NEG should be no more than maybe 1-2V which key in "run", engine stopped, and with 6-9 or so on the coil +
THIS INDICATES that the coil is not drawing current through the box. ECU Box ground, intermittent coil, intermittent in coil NEG wire to box, or ECU connector terminal for coil NEG, or intermittent ECU OR ECU may be losing power, from it's box wire terminal, that wire goes over to "run" voltage.