RSQ3 Fuel Injection Failure Symptoms Point to Repairs

Recently had similar symptoms with my RS4 (2018, gasoline). The fuel injection system requires proper diagnosis as these issues typically stem from either failing injectors or compromised connections. The power loss combined with increased fuel consumption points strongly toward faulty fuel injectors. In my case, carbon buildup was causing improper atomization, leading to incomplete combustion. The smoke during acceleration confirms this suspicion, as unburned fuel creates visible exhaust. The stalling at idle is particularly concerning, as it indicates the engine is not receiving consistent fuel delivery. My repair involved removing and cleaning all injectors, replacing two that were beyond salvage, and addressing corroded wiring connections to the injection control module. This is a serious issue requiring immediate attention, as continued operation risks further engine damage. The job needs specialized diagnostic equipment to properly assess injection timing and spray patterns. A certified technician with experience in direct injection systems should handle this repair. The symptoms match what many high-performance engines face after significant mileage, especially with high-pressure fuel systems. Proper maintenance and high-quality fuel help prevent premature injector wear.

Thanks for sharing your experience with the RS4. I had the exact same issue with my RSQ3 last year, the performance drop and excessive fuel consumption were really concerning. The stalling got so bad I could barely drive it. After reading about similar cases in this forum, I finally got it checked. My mechanic found carbon deposits in the injection system, exactly as you described. The engine maintenance involved a full system cleaning and replacing one faulty injector that was causing a minor fuel leak. Did you track your fuel consumption after the repair? Also curious about the final cost of your fix, if you dont mind sharing. Mine has been running smoothly since the work, but I keep monitoring the performance just in case something else develops.

Glad your RSQ3 issue got resolved. After getting my RS4 fixed at the garage last week, the injection system fault has been completely eliminated. The entire repair was surprisingly straightforward, it turned out to be a loose cable connection to the fuel system control unit that was causing all those symptoms. The power output is back to normal and the engine runs perfectly smooth again during idle. Total maintenance cost came to 95 Euro for fixing the faulty connection, which was a relief since I initially feared needing multiple injector replacements like in your case. My fuel consumption has returned to standard levels, about 25% less than when the problem was active. Regular system checks are crucial though. I schedule engine maintenance every 15000km now to catch any potential issues early, especially with these high-performance petrol motors.

Thanks everyone for the helpful responses. I took my RSQ3 to my mechanic last week after seeing all the similar experiences here. The fuel injection system needed a thorough cleaning and the power issues were exactly as described. The engine maintenance took about 4 hours. They found carbon buildup causing a major leak in two injectors. Total repair cost was 480 Euro, including parts and labor. A bit steep, but worth every cent considering the system is running perfectly now. The difference in performance is incredible, no more stalling, smoke is gone, and my fuel consumption dropped back to normal. The mechanic showed me the dirty injectors and explained how carbon deposits can wreck the entire fuel system over time. Really appreciate the advice here. Will definitely keep up with regular maintenance checks to avoid similar issues in the future. Currently monitoring the engine performance just to be sure everything stays in order.