Hello ! I have been having hard starting issues when the car is warm. When cold, it fires right up. It always runs/idles great. When it's warm or not a completely cold start, it will crank for 10 seconds before it fires up. If I crank it for 3-5 seconds, stop and crank again, it will fire right up.
2002 WS6 m6, stock except Magnaflow catback, 40,000 miles. I have owned it since 2005 and this was never an issue.
From 2018 to 2024 I only put on 1400 miles. The car did sit a lot them years, but I would at least run it around the block occasionally. The longest it went without fresh fuel was maybe 9 months. I never used fuel stabilizers/seafoam etc.
I have been through 5-7 tanks of fresh gas this year, but the problem continues. Where can i start looking for the issue ?

 

Maybe the Crank Sensor. Have you checked the Fuel Pressure to see what it is when it's warm? I'm leaning more towards the Crank Sensor though..

 

I don't have a gauge to check the fuel pressure. The crank sensor don't sound like an easy repair. Is there a way to check the crank sensor ?

 

See if the car has any codes in the system that are active pending ones, not codes that have been there for a while. Crank Sensor is located behind the Starter, once you get that out of the way it's easy to do. Overtime heat kills them and the symptoms are what you listed above.