Engine cutting out - crank position sensor?

My son reported his Fabia 2 cut out several times on 30 minute dual carriageway run yesterday - dangerous of course! It restarted each time when he dropped down to 4th and applied throttle. He's not even certain that the engine cut out - just that he experienced complete loss of power. No CEL showing and I've plugged in a VW compatible scanner which reports no codes stored. Would an intermittent CPS record a fault code, or does the ECU ignore a crank sensor failure and just cut fuel?

I've recently given car full service including new fuel filter and spark plugs (the old ones were perfect colour). Have had no running problems since purchase six months ago, only usual door lock/mirror control electrical gremlins which I've fixed.

Any other ideas on what to look for? Car back in garage but I won't be able to work on her till weekend. Wondered if could be something simple like ignition switch so will wiggle this, and wiggle any critical connectors while idling. Does the distributor to individual coils ever go bad? It's only a cheap £20 code reader but has picked up stored codes in past.

Thanks for any advice. 

Edited 31 October, 20187 yr by Stratfordade