I sold my old A2 1.4 TDI to a good friend a couple of years ago... He loves it (I've now got a newer one, so everybody's happy) but recently it's developed an occasional problem... It always starts when cold, but sometimes, having warmed up properly but then briefly stopped, it just won't start. My mate just has to wait in the car, trying it every 5 mins or so, and then it'll eventually get going again, sometimes after as long as half an hour... He's had a diag test at his local (non specialist) garage, but as it's intermittent, no fault has been diagnosed. Has anybody got any ideas? Thanks...