what I would do is with some made up jumper wires with alligator clips/specific terminals as needed I would jump from a 12V source like the batt stud on the starter relay to/thru the ballast to the coil/ECU (duplicate ALL of the ign1/ign2 circuits) & pull the ign2 wire when (if) it starts. this takes the wiring completely out of the picture & only leaves the hard components which most you have replaced then if we are good so far we can start to remove one jumper at a time & restart it to pin down which circuit has the open or intermittent connection.