VW Up Fuel System Failure Causes Multiple Issues

I had a similar issue with my VW Polo from 2014 with the 1.2 TSI gasoline engine. Having some experience with fuel system problems, the symptoms you describe match what I encountered. The power loss and rough idle turned out to be caused by a faulty wiring connection to the fuel injectors. The workshop performed a diagnostic scan which revealed irregular fuel injection patterns. After inspecting the wiring harness, they found a damaged connector that was causing intermittent electrical issues. The repair involved replacing the affected wiring and connectors, costing 95€ including labor. The fix completely resolved the stalling, smoke, and fuel consumption problems. The engine power returned to normal immediately. Before taking it to the workshop, make sure they check: Fuel pressure readings, Injector electrical signals, Wiring harness condition, Fuel pump operation To provide more specific guidance about your situation, could you share: Engine size and type, Current mileage, When did these symptoms first appear, Have you noticed any check engine lights This information would help identify if your issue matches what I experienced or might be something different in the fuel delivery system.

Just had my recent maintenance service last week, so wanted to share my experience with a very similar issue. My injector wiring was also failing, causing power loss and excessive fuel consumption. The mechanic ran a complete fuel system diagnostic that confirmed unstable injection patterns. The actual fix turned out to be simpler than expected, just needed cleaning of the injectors and replacing one damaged connector. Total repair cost was 180€. The engine now runs smoothly again with normal power delivery. Would definitely recommend getting the fuel pressure and injection timing checked first before assuming worst-case scenarios. A thorough fuel system inspection might reveal similar electrical issues rather than mechanical problems with the injectors themselves. The diagnostic fee was worth it since it prevented unnecessarily replacing expensive components.

Thanks for the follow-up about your repair experience. Great to hear you got it sorted with just a cleaning and connector replacement rather than needing new injectors. On my Polo, I initially worried the entire injection system needed replacement, but the diagnostic approach saved money by identifying the actual issue. Since fixing those wiring problems, the engine has performed flawlessly with no return of the smoke or stalling. For others reading with similar symptoms, air leaks in the system can mimic injection problems, so having a complete fuel system and air intake check is crucial. Our cases show why proper diagnostics matter instead of just replacing parts. Did your mechanic mention how they spotted the failing connector? In my case, they used specialized testing equipment to trace the electrical signals through the system. This kind of systematic troubleshooting seems key for these fuel delivery issues. The difference in repair costs makes sense, mine only needed the wiring fix while yours included a full injector cleaning service. Both solutions highlight how electrical issues often underlie fuel system problems in these engines.

Thanks everyone for the helpful discussion. The repair solved my VW Up issues completely, and I wanted to share the final outcome. The diagnostic tests proved essential since they identified both the bad connector and dirty injectors affecting fuel delivery. The engine performance is now back to normal with proper power delivery and no more stalling. Total cost breakdown: System diagnostics: 45€, Injector cleaning: 85€, Connector replacement: 50€ Key learning points from this experience: Electrical issues can cause major fuel system problems, Proper testing prevents unnecessary parts replacement, Air and fuel delivery problems show similar symptoms, Professional diagnostics are worth the initial cost Really appreciate the shared experiences that helped me understand the likely causes. The systematic approach to troubleshooting these fuel injection problems saved both time and money in the end. Getting the air-fuel mixture right made all the difference. No more black smoke, stable idle, and power is completely restored. For anyone facing similar symptoms, definitely get the electrical connections checked before assuming mechanical failures.