Q8 Hybrid Fuel System Failure Needs Expert Diagnosis

Having experienced similar symptoms with my 2020 Audi Q7 hybrid, this sounds like a fuel delivery system problem, but not necessarily the fuel pump itself. The key automotive diagnosis indicators point toward a faulty fuel injector connection or wiring harness issue. Last month, my vehicle displayed identical performance issues, rough idling, intermittent starting problems, and increased fuel consumption. After proper diagnostics, the root cause was traced to corroded connector pins in the fuel injector wiring harness, affecting the signal transmission between the engine control unit and injectors. This is a serious issue requiring immediate attention, as continued operation can lead to catalytic converter damage and complete engine failure. The repair involves: Full diagnostic scan, Fuel injector circuit testing, Wiring harness inspection, Connector replacement if corroded, System reprogramming The car performance returned to normal after addressing these connection issues. This is a known weakness point in some hybrid models with high mileage. Would strongly recommend having a certified technician perform voltage drop tests across the fuel system before replacing the entire pump assembly. Auto repair for this specific issue requires specialized diagnostic equipment to properly identify which circuit is failing.

Thanks for sharing your experience with the injector wiring issue. My car ended up having a similar problem last year and the car performance improved dramatically after the fix. The fuel delivery system is definitely a common trouble spot in these models. Did your repair also involve a full system reset after the work was done? And can you remember roughly what the total cost was? Just wondering if any other issues popped up since the repair was completed, sometimes these fuel system problems can cascade if not caught early enough. The situation with my hybrid Q8 ended up being pretty complex, with multiple parts of the fuel pump assembly needing attention. Really hoping yours was a simpler fix than mine turned out to be.

After getting the automotive diagnosis completed and the repair work done, my Q7s fuel pump defective condition turned out to be much simpler than yours. The technician found it was just a faulty cable connection causing the fuel delivery issues, which was fixed for 95 Euro. The repair included a full system reset and diagnostic scan to ensure proper gasoline delivery after the work. Since fixing that connection issue, the engine stalling problems completely disappeared and fuel consumption returned to normal levels. No cascade failures or additional fuel system problems have occurred in the months following the repair. Interesting how these hybrid models can show such similar symptoms from different root causes. While your Q8 needed extensive fuel pump work, my simpler wiring fix resolved all the performance issues. Regular system checks seem crucial to catch these problems before they escalate into more serious failures.

Thanks for the input. After getting multiple opinions, I finally took my Q8 to a certified technician who specializes in hybrid fuel systems. The car mechanics found both wiring issues and a failing fuel pump assembly. The repair process included: Complete fuel system diagnostic testing, Replacement of damaged wiring harness, New fuel pump installation, Full computer system reset Total cost came to 1450 Euro but the engine stalling is completely gone and fuel consumption is back to normal. The auto repair shop also found early signs of injector wear which they documented for future reference. Been driving for 2 weeks since the fix with no issues. The car runs smoother than before and starts perfectly every time. Really glad I got it sorted before any cascade failures could develop. Just wanted to close the loop and share what fixed my specific case since these hybrid fuel system problems can be tricky to diagnose.