X5 4.4i N62 intermittent weird starts

[brokenX544]

Hi everyone,

I have a very weird issue on my new to me X5 4.4i LCI from 2005 with 180000km (110k miles I guess).
The car died a few days ago and it turned out to be the fuel pump. We changed it, and the car started struggling to start when hot. We then changed the spark plugs and the car seemed fixed, until a few days ago where it did not want to start in the morning. All that while running what seemed to be perfectly the day before. It had done like 1600 km (1000 miles) in the days before that without any hiccup.
So after a few failed start-up attempts we called bmw and their assistance came and managed to start the car by cranking for like 20 secs (felt like eternity) and giving it full gas.
Now it sometimes struggle like that, cold or hot, and each time we manage to start it by giving it full throttle and wait. The Bmw guys said it was like the engine was flooded with gas.
Not one single code on the OBD reader, and all values when running look to be in the correct range.
We plan on replacing the fuel filter, but what could be the issue?
I have a video of it trying to start but I dont think I can put it here.

Thanks a lot for your time and cheers from Switzerland