Electronic ignition help needed !!

I just had my slant 6 upgraded to electronic ignition (MP kit with blue ecu). The car started and ran perfectly (better than it has ever run) when the install was completed. Test drive - perfect- no problems. Started every time all day until... The car was moved out of the garage. When I went to leave, it wouldn't start. No spark - but it cranked fine. After 10 minutes chasing the problem, it corrected itself and ran fine.

Three days ago, I replaced the battery (old battery needed to go), started it again and went out for a drive. I stopped at 3 different places. It started every time and had no problems.

Today, I changed the oil and filter, went to start it and again - it does not start.

I used a multi-meter to check power. Everything seems fine. Cranks great but no start. I changed the ballast resister to no avail. I checked all the connections and everything seems fine. What am I overlooking? I need this thing in good order by next Friday when it goes in for a new top. What are the chances that the ECU is bad or that I need to replace the coil? The carb is getting fuel and I know I didn't flood it. Plugs are year old. Any Ideas? Thanks