Intermittent None Start

[aldworth33 45 1 Cars]

My XU10J4RS converted 205 occasionally has a hissy fit and refuses to start, it turns over but won't fire. I think it's getting fuel but no spark. If I leave it for 10 or hit the kill switch then re try after a min or so it fire up 1st time. This only happens once a month or so and I use the car daily so isn't the biggest pain, just wondered if anyone's had the same fault and knows how to sort it?

 

Cheers Aidan