Fuel distributor injection pump fabia 1.9sdi

Y reg Fabia 1.9 Sdi

won't start when warm (seems common) (engine turning over but not firing)

Will conk out idling (eg stuck in slow traffic) for more than 6-7mins, then won't start.

(Power sterring needs new control travel sensor (4562) but thats a different issue I think)

Getting following fault codes 4632 - Fuel distributor injection pump at maximum stop & 4633 - Fuel distributor injection pump at minimum stop.

Has anyone seen anything similar and knows how to fix it?

I really don't want to have to replace evreything, as some have suggested new fuel injector, new starter motor.

Thanks for any help