Volkswagen polo 1.2 starting problem

[Aqibraja_96]

Mk5 1.2 3 cyl 60bph

car starts fine when engine cold. After driving refuses to start it just keeps cranking.

 

changed all spark plugs, all coil packs, engine loom wiring harness and starter motor. Problem still persists.

 

any idea what this could be? Thanks 

[Volkswagen Owners Club]

I wonder if it could be the crankshaft sensor as when these fail it is usually when they get hot
Try fitting a new one and see how you get on