my baby has let me down

[webs289]

so last weekend on the way home from turin, my 2004 4.0tdi shudderd badly as if a tyre had let go, as i started to pull over onto the hard shoulder it cut out completely and wont restart. It was recoverd to a garage in parma. The day after the italian mechanic said he thinks a valve is bent, i am very dubious about this and think the fuel pump has gone or something along those lines. Any one any ideas? The car is due to be shipped back to audi on the 12oct, would prefer to buy a copy of vagcom and try yo self diagnose but some leads of where to start would be nice:-)