RS4 Stalling and Power Loss Points to Fuel System Fix

As an RS5 owner dealing with similar symptoms last month, this strongly indicates a failing high pressure fuel pump or faulty fuel regulator. The stalling, power loss, and check engine light match typical fuel delivery system issues that affect engine performance. When my car showed these symptoms, the automotive repair revealed a defective high pressure pump that was unable to maintain proper fuel pressure. This is a serious issue requiring immediate attention since continued driving risks damaging the fuel injection system and causing complete engine misfire. The repair involved replacing the entire high pressure pump assembly along with the fuel regulator to restore proper fuel economy and engine performance. The car needed to stay at the shop for 2 days due to the complexity of accessing and testing the fuel system components. These symptoms should not be ignored, the stalling will likely get worse and could leave you stranded. A certified shop can perform proper diagnostics to confirm if its the fuel regulator or pump. They will need specialized equipment to test fuel pressure and analyze fuel delivery rates. Given your RS4 is nearly new, this repair should be covered under warranty. Would recommend contacting the dealer service department rather than an independent shop for this specific issue.

Thanks for sharing your RS5 experience. That really helps confirm my suspicions about the fuel system being the culprit. Car maintenance issues like this can be quite concerning. Just curious, do you remember the total repair costs for your fuel pump and regulator replacement? Also wondering if youve had any recurring engine misfire issues or check engine lights since the work was done? My fuel efficiency has also tanked lately which makes me think its definitely fuel system related.

Had the fuel system repair done 3 weeks ago and everything is running perfectly now. The car sensors are all showing normal readings and the rough idling completely disappeared after they fixed the defective fuel volume regulator. The total cost came to 1510 Euro for replacing the high pressure pump. Money well spent considering how smooth the engine runs now. Car maintenance records show the fuel efficiency is back to normal levels and there have been no check engine lights or misfires since the automotive repair. The mechanic did a thorough job testing all fuel delivery components to ensure there were no related issues. Looking back, getting it fixed promptly was the right call, these fuel system problems tend to cascade if left unchecked. The engine performance is now exactly what you expect from an RS5, with perfect idle and full power restored. Can confirm this repair fully resolved all the symptoms you described.

Following my mechanic visit last week, I can finally share how everything turned out. The automotive repair confirmed it was indeed the fuel system, specifically a faulty fuel volume regulator just as suspected. After running diagnostics, they found the fuel pressure was dropping below specs during idle, causing the rough idling and power issues. The repair took about 4 hours and cost 890 Euro under warranty, only paying for some additional preventive maintenance they recommended. Car maintenance records show the fuel efficiency has improved significantly since the fix. The engine misfire symptoms have completely disappeared. No more stalling, check engine lights, or power loss issues. The idle is smooth again and the car feels back to its proper performance level. Really glad I got this sorted before it could cause any additional problems with the fuel injection system. For anyone else facing similar issues with their RS4, definitely get it checked out quickly. These symptoms clearly point to fuel delivery problems that need immediate attention.