Coil sparks when you cycle the ign but no spark when cranking?. I would check the distributer hall sensor. Pull the the three wire plug from the distributer and if you look at the black plastic socket on the dizzy you will see it is marked with a +, - and a o. The + should be battery voltage when the ign is on, - is earth and the o is the switch from the hall sensor. If you link the 0 and - on the wire side,there should be a spark when you make and brake the connection. If there is a spark it looks like a hall sensor fault, if no spark and the live and earth are OK, poss ign module or coil fault. If you have a spark at the coil lead but not at the plugs, check the cap and rotor.
Hope this helps.
Steve.