I've had this as well in my last 164.
Here are some ideas.
- Leaky injectors. I'm told that these can flood the engine after shutoff. Perhaps remove the injectors and have them cleaned/tested?
- Coolant temperature sensor. If faulty, the injection system thinks the engine is 'cold' when it is hot, and injects too much fuel.
- Normal behaviour. It does say in the handbook to press the accelerator pedal if the engine does not start...
Others will have some more specific advice but those are the things that come to mind first.
Cheers,
-Alex