ecu box problem

You could very well have a break or a poor crimp where the wire(s) connect to the terminals in the connector boot. That is one reason when guys have problems with these, I always suggest working the connectors in/ out

For future "tuck it away" the distributor connector is far more problematic, as there is almost zero current through it. The slightest bit of "loose" or corrosion can stop the trigger signal.