I'v got this issue on my 1.9 tdi 8p1. It's been a problem ever since i'v owned the car (18 months).
The car starts absolutely fine when cold, literally a millisecond after turning over the key. The problem i get is when the engine has been running a long or short while and warmed up, When re-starting, it does start eventually but the turning over seems like a lifetime. I can recall on very few occasions through our rare summer days, If i didn't start the car till afternoon on a hot day i would sometimes get a similar issue with delayed starting.
Anybody had a similar issue or any idea on the culprit?