Best way to check this is Get a timing light and get a Nissan Electrical Manual.Find which wire is which before and after the Ignitor. and check from there,You find that if its not firing on the light before the ignitor you have a problem from the ecu to there.If it firing before the ignitor and not after its the problem.
if its got no Ignitor,You might find a wire is cut or broken and test the same way.If you cannot get a spark still,its the ECU