Did you check for Fault codes?

Your coolant temp sensor (the green one or black on early models) is ok?

Also the file attached is the eeprom (95040) not the flash .

@PaulB

There are no fault codes. I don't get it, it's like the car doenst save all the fault codes in my case. Removing the sai should also show me the fault code for that, but nothing in there.
I changed already a lot of stuff (Camshaft, Temp, Spark plugs, Ignition coils etc.).
It helped for about 10 days and then started again.

@_nameless

the engine was completely overhauled. Couldn't the problem be more likely to be a leak? I removed the intake manifold and everything on the fourth cylinder was very wet (the gasket and on the intake), the injector was also very loose as if it was no longer sealing properly. The crankshaft ventilation is tight, the air recirculation valve also works.
Compression was also measured and was also OK.
Does anyone here have the workshop manual so that I can check the vacuum hoses to see if they are connected correctly?
Unfortunately, I can't see any misfires in VCDS either, as the blocks are only empty. Does anyone know if the TT year 2000 had this function at all?

Like I already posted, the compression was ok. So no loss of compression. The other thing is, when the car starts directly with 800 rpm everything run there was no problem and then, when it goes up to 1200 rpm on first start, the problem starts after few seconds of no issues on the start.
If the compression were not there, the car would have to run badly right from the start, but it does not. Or am I wrong? It just takes a few seconds until it starts and then dies.

You said cyl was was wet.  Wet with what?  What _nameless is suggesting seems to match it being wet...

it's yellow so it must be the fuel that is dripping.

@aef

Sorry, my mistake. I'll put it on the next todo and check the whole thing. Thanks!