My Audi 2.5tdi 101K miles has today developed a stalling problem. when the engine is idling, the car will stall after a few seconds. It happens about 30% of the time and occurs in any gear, N, D, P, or R. I filled up with fuel earlier today from Q8 and am beginning to wonder whether it is bad fuel. The car runs normally and doesn't seem to lose any power but the fuel consumption reading appears to have increased.

Has anyone any ideas.
Regards