take wire off of the negative coil primary terminal & w a jumper wire w alligator clips jump from this TERMINAL to good ground repeatedly tap tap like Morse Code & (w key on) see if that makes a spark from the coil to dist wire held 1/4" from ground. If yes I'd suspect the ECU, or the ECU ground, or the dist coil pickup (in that order). If no spark either the coil positive primary terminal is not getting fire via the ballast or the coil itself is bad. Check/clean the ECU base/body, ohm out the dist pickup leads (iirc 2-400 ohms) but the specs are in the archives or use a spare dist & spin it by hand (key on) & see if it now sparks, sub in a known good ECU (they (some of my used ones) have gone bad from sitting on the shelf).