Get a noid light (cheap tool used to check fuel injectors are getting spark and timed correctly so you can check that as well)

and plug it into the low tension plug that enters the coil; it should flash when you turn the engine over. Then put and old spark plug with the gap opened slightly to 1.5mm gap and earthed on the block or head, at the distributor end of the HT lead that comes from the coil to the distributor and see if it flashes brightly when you turn the engine over. Then do the same at the plug ends of the HT leads..
Also check the ECU earth in the passenger side footwell is good and firm (the screw hole can open up and lose the earth connection so it works on and off).