VW Beetle Stalling: Fuel Pressure Regulator at Fault

I had a similar issue with my 2013 VW Golf with the 2.0L TSI engine. I have some experience working on VWs and this particular problem showed similar symptoms to yours with rough idle and power loss. The fuel pressure sensor was throwing codes after I changed the fuel filter. The engine would stall at idle and experienced significant power reduction, affecting fuel efficiency. Initially thought it was the fuel pump, but the workshop diagnosed it as an installation error with the filter causing irregular fuel pressure readings. The fix was straightforward, they properly reseated the filter, cleared the codes, and performed a proper pressure test. Total cost was 45€ for diagnostics and labor. The engine misfire symptoms disappeared completely after this. Before suggesting specific solutions for your Beetle, could you share: Engine size and type, Current mileage, Any recent maintenance work, Specific error codes if you have them, Does the rough idle happen only when the engine is cold or all the time? This information would help determine if your issue matches what I experienced or if it might be something different in the fuel delivery system.

Just had my 29k service last month and started noticing these symptoms shortly after. The mechanic also tested the fuel pressure, which showed irregular readings between 2-3 bar at idle. Good point about checking cold vs warm behavior, in my case it definitely gets worse when the engine is warm. I noticed the pressure drop tends to be more severe after about 10 minutes of driving. After reading about similar cases, I am wondering if we should look more at the fuel pump rather than just the pressure regulator. The stalling seems worse when fuel level is below half tank, which might point to a failing pump. Would be great to hear if anyone else observed this tank level correlation with their fuel delivery issues.

Thanks for that additional detail. Your symptoms definitely differ from my Golf case, especially with the warm engine behavior and fuel level correlation. After dealing with my initial fuel pressure problems, I actually did end up having a failing fuel pump about 6 months later, showing very similar symptoms to what you describe. When my fuel pump started failing, I noticed the same correlation with fuel level that you mentioned. The check engine light would flicker on more frequently below half tank, and the engine misfire became more pronounced. The pressure readings I got were also unstable, fluctuating between 2-2.5 bar. The fuel system diagnosis revealed the pump was struggling to maintain consistent pressure in the fuel rail, especially at higher temperatures. My mechanic performed a fuel pressure drop test that confirmed the pump was losing efficiency. Rather than just replacing the pressure regulator, we ended up installing a new fuel pump assembly. Total repair cost was around 450€ including parts and labor. The fix completely resolved both the stalling and power loss issues. Based on your description, I strongly suspect your fuel pump is showing the same wear pattern mine did, rather than just a pressure regulator problem. Consider getting the fuel pump tested specifically while the tank is below half full, as this will make any pressure inconsistencies more apparent during diagnosis.

Thanks for the detailed feedback about the fuel pump symptoms. The tank level correlation really helps confirm my suspicions. These fuel system issues can be tricky to diagnose, but the symptoms match up perfectly with what you experienced, especially the pressure readings and behavior changes with a warm engine. Going to schedule a proper fuel pressure drop test this week, specifically requesting they check it with a low tank like you suggested. Makes sense to look at the entire fuel pump assembly rather than just focusing on the pressure regulator. The 450€ repair cost seems reasonable considering the comprehensive fix you got. One last question about your repair, did you notice any difference in fuel efficiency after the pump replacement? My current fuel consumption seems higher than normal, and I am wondering if that might improve once the fuel delivery system is working properly again.