Why does car struggle to start when engine is warm?

Hi, my name is Devin. I am an auto repair expert with the Car Genius team here at RepairPal. I’m sorry to hear you're having trouble with your A8. A hard start when the engine is warm can point to a few possible issues, like a failing crankshaft position sensor, weak fuel pressure, or even a vapor lock situation. When the engine heats up, electrical components like sensors can start to fail intermittently, and fuel system components may struggle to maintain proper pressure. Checking for stored trouble codes and testing fuel pressure when the issue occurs can help pinpoint the cause. If you need more advice, have any other questions about your vehicle, or would like to get connected to a RepairPal Certified shop near you, we have you covered. Give us a call at 877-913-1554, and we will happily help you out!