Cold start problems Golf 4 TDI 90hp

Hello,
I'm having trouble starting my engine; it takes a very long time to start. I suspect there might be air in the fuel system, which theoretically shouldn't be possible because the system is self-bleeding. When reading the engine control unit (ECU) with VAG-COM, no control-related errors were found.

Hello,

Please adhere to the forum rules and use the search function before posting.
There's quite a bit of information available on the topic of warm start.