RS3 Cold Start Issues Point to Injector Problems

I dealt with a very similar fuel system issue on my 2021 RS4. Had some experience with fuel delivery problems before, so I recognized the symptoms right away. The hard starting problems started exactly like yours, rough running after cold starts with occasional engine misfire events. The fuel rail pressure was inconsistent during startups, pointing toward injector problems. After proper diagnosis at the workshop including: Fuel pressure testing, Injector electrical signal verification, Cold start enrichment analysis, Leak-down testing of injectors They confirmed one faulty injector that was not atomizing fuel correctly during cold starts. Total repair cost was 515 Euro including: New injector, Programming/coding, Pressure system cleaning, Labor The fix completely resolved the cold start issues and restored normal operation. Before suggesting specific solutions for your case, could you share: Current mileage? Check engine light status? Any fuel system maintenance history? Specific error codes if scanned? This would help determine if your symptoms match my experience with the faulty injector scenario.

Thanks for sharing your experience. My RS3 has 195097 KM and just had its annual service last month. The workshop scan showed P0201 injector circuit malfunction code. This confirms my suspicion about the fuel system causing the hard starting issues. Based on your repair details, seems my case points to similar injector problems affecting proper fuel delivery during cold starts. The engine misfire symptoms match exactly what you described. Good to know a full injector replacement resolved it completely. Will schedule diagnostic testing to verify if I am dealing with the same root cause. The repair cost seems reasonable if it fully fixes these cold start troubles.

Thanks for the mileage and error code details. Yes, that P0201 code on your RS3 strongly indicates an injector circuit issue, matching the symptoms I encountered. The rough idle and hard starting behavior is a classic sign when the fuel system cant maintain proper pressure during cold starts. Since your symptoms mirror my previous experience with the faulty injector, a similar repair approach would likely resolve it. In my case, the fuel rail pressure inconsistency during cold starts was the key indicator that helped pinpoint the failing injector. One recommendation based on my repair process: have them perform a complete fuel system cleaning when replacing the injector. This extra step helped prevent any contamination issues from affecting the new components in my RS4. The 195097 KM on your engine is actually close to when my injector issues developed, suggesting normal wear patterns in these fuel system components. Once repaired, you should notice immediate improvement in cold start performance and elimination of those engine misfire events. Keep us updated on the diagnostic results. The repair cost will likely be in a similar range to what I paid, assuming they find the same root cause.

Thanks everyone for the detailed replies about fuel delivery problems. Really helped clarify what I am dealing with on my RS3. I scheduled the diagnostic testing for next week. The P0201 code and hard starting symptoms match perfectly with the faulty injector scenario described. Good to know the rough idle and engine misfire events during cold starts were resolved after injector replacement. My 195097 KM definitely suggests normal wear could be affecting fuel system performance. Will make sure they include a complete fuel rail and injector cleaning as part of the repair process. The quoted repair cost around 500 Euro seems fair considering it includes: New injector, System cleaning, Programming, Labor Will report back once the work is done. Hoping for the same positive results in resolving these cold start troubles. Thanks again for sharing the helpful repair details and diagnostic steps.