check:
1.) ignition fuse [blown?]
2.) cap and rotor [burn marks, scorching, carbon build up all hurt spark]
3.) spark plugs [closed gap?, oil fouled?, excessive carbon?]
4.) wires [burn marks?, loose connections?, hard spots in the insulation?]
5.) ICM [wired wrong?, dropped?] unfortunately, the only way to test one is to replace it.
6.) coil [getting hot?, being charged properly?, heavy case rust?, no oil left to hear in it?]
7.) wire leads coming out of distributor body [properly wired?, good connection?, chaffed, stretched or burned insulation?]
8.) ECU feeding/reading correct wires for the distributor?

That's the usual order I go in, if you don't find anything wrong after going through the list, nothing's wrong, or the distributor is trash. Good luck.