Audi S3's Fuel System Woes: Power Loss and Stalling

As someone with moderate experience in automotive repair, I encountered a very similar issue with my 2019 Audi RS3. The symptoms you describe match exactly what I experienced, poor fuel economy, stalling, and reduced power output. After multiple diagnostic tests, the workshop identified a defective high pressure fuel pump as the root cause. The repair cost came to 1510 Euro, including parts and labor. The fuel efficiency improved dramatically after the replacement, and the engine misfire issues completely disappeared. The workshop performed several steps for proper diagnosis: Complete fuel system pressure test, Electronic diagnostic scan, Fuel delivery rate measurement, Performance data logging For adequate car maintenance and to prevent future issues, they also inspected the entire fuel delivery system and cleaned the fuel injectors. To provide more specific advice for your situation, could you share: Current mileage, Last fuel system service date, Any recent changes in fuel type, Whether the issues started gradually or suddenly, Any unusual sounds from the engine bay This information would help determine if your S3 is facing the same fuel system problems I encountered with my RS3.

After 176917KM and regular maintenance, I experienced the exact symptoms you describe. Turned out my high pressure fuel pump was failing, causing similar rough idling and power issues. The diagnosis revealed inconsistent fuel injection patterns, which explains the poor fuel efficiency and stalling. A full diagnostic check and fuel system pressure test confirmed the pump failure. The repair restored proper fuel economy and resolved all power delivery problems. My advice would be to get a proper diagnostic scan to verify if you are dealing with the same issue. The fix cost around 1500 Euro but completely resolved the problems. This seems to be a known weak point that can develop on these engines despite regular maintenance.

Yes, definitely sounds like we had the identical issue. Just to follow up on my previous repair experience with the high pressure fuel pump, after about 20000km since the replacement, the fuel efficiency has remained consistently good and no rough idling has returned. The car sensors are all showing normal readings now, and the automotive repair shop did a great job identifying the root cause quickly through their diagnostic process. One thing I learned is that fuel injection problems on these engines can sometimes mask themselves as other issues, which is why proper diagnostics are so crucial. The workshop mentioned this is a fairly common wear item on our engine type, even with careful maintenance. Given your mileage is similar to what mine was when the issue occurred, it really does point to the fuel pump. The repair cost you mentioned aligns exactly with what I paid, suggesting standard pricing for this type of work. Would recommend keeping an eye on your fuel consumption numbers for the next few months, a properly functioning pump should show noticeably better efficiency numbers compared to when it was failing.

Thanks for all the feedback about the high pressure fuel pump issues. It's definitely reassuring to know others have experienced and resolved the same problem. My car has been running flawlessly since the repair. The car sensors are all showing normal readings and fuel efficiency has improved dramatically. No more rough idling or power delivery issues. The fuel injection system is working perfectly now, and the car maintenance schedule is back on track. For anyone else experiencing similar symptoms, my advice would be to get it properly diagnosed right away. The 1500 Euro repair cost was worth it to restore proper performance and prevent potential damage to other components. The car runs like new again after addressing the failing pump. Interesting to hear this seems to be a common wear point around this mileage. At least we now know what to watch for in terms of early warning signs like inconsistent power and poor fuel economy. Really appreciate everyone sharing their experiences and repair details.