My 92 Passat L Turbo Diesel won't start when the engine is warm.
No problem from cold but if I stop after a drive, she won't fire again until she is cold again.
Also cuts out sometimes if crawling in slow traffic for a mile or so. Then have to wait for 45 mins for her to cool down to start again from cold.
Once she starts, she drives like a bird.
It's driving me mad, not to mention having to push her off gas forecourts every time I stop to fill up. My garage cannot trace problem.
Help! Please.

By won't start do you mean it won't crank as in the starter is not working? That is a common problem, especially on the automatic starters.

No. Starter is fine. It seems to be a fuel starvation problem of some sort. When warm, the engine turns over fine but no hint of it firing. After 30-45 minutes when she is cold, she fires first time.

Have they checked the fuel shutdown solenoid when it won't start? Does the the car have an automatic transmission?

I'll ask them to check. Would the temperature affect that? She doesn't overheat, it's just when she has been running at normal temperature.
It's a manual, not an automatic

Sure, when hot the solenoid can have too much resistance for the electrical system/wiring to get it to open again. Or it can be physically sticking after the internal metal parts expand.