I have had two cars recently where breakdown chaps have correctly diagnosed a faulty in tank lift pump on the CR TDI 2 litre A3/Golf 6 but when quickly re-assembling to recover the car, they put the hose fittings on the tank the wrong way around as it looks more correct than the right way. When the garage who fixes the car fits a new pump, they repeat the error. The REALLY annoying thing is that they run perfectly like this until every now and again they cut out and won't re-start or start poorly from cold, a real nightmare to track down initially but now I know the signs.