VW Up Cold Start Struggles: Bad Injector Alert

Had the exact same fuel injection problems on my VW Polo TSI (2017). Cold start problems started gradually, rough idle, stuttering during first minutes of operation. Initially thought it was just bad fuel quality. The injector test revealed two faulty injectors causing incomplete fuel delivery during cold starts. The diagnosis showed inconsistent spray patterns and poor atomization. The repair involved replacing both injectors and performing a thorough injector cleaning on the remaining ones. This was a serious issue that needed immediate attention, as faulty injectors can cause long-term engine damage and increased fuel consumption. After replacement, the cold start problems disappeared completely and engine performance returned to normal. If your symptoms match, recommend getting a professional fuel injection diagnostic test. Modern fuel systems are complex and require specialized testing equipment to properly diagnose. The injectors might just need professional cleaning, but if testing shows failed units, replacement is the only reliable fix. Worth noting that cold start problems can worsen quickly if ignored, potentially leading to harder starts and rough running conditions even when warm.

Thanks for sharing your experience. My Up had those exact hard starting symptoms last winter. The injector test also showed poor spray patterns in my case. Really helpful to know the cleaning and replacement fixed it completely. Would you remember roughly how much you paid for the repair? Have you experienced any other fuel system issues since getting it fixed? Mine is due for service soon and I want to budget properly since I might need a complete fuel injection system overhaul. The rough idle is getting more noticeable each morning.

Got my car back from the mechanic last week and can confirm the faulty cold start injector was the culprit. Total repair cost was 515€ which included replacing the defective injection valve and running a complete fuel rail diagnostic. The rough idle issues disappeared immediately after the repair. Cold starts are now smooth and the engine runs perfectly from the first turn of the key. Looking back, the fuel delivery problems were quite obvious, the stuttering and inconsistent performance during cold starts were classic signs of injector failure. Have not experienced any fuel system problems since the fix. The mechanic did mention regular fuel system maintenance and using quality fuel helps prevent future injector issues. Running some injector cleaner through the system every few months is also good practice. For reference, the complete diagnostic test was essential in pinpointing the exact issue. Modern fuel injection systems are complex, so proper testing saves money by avoiding unnecessary parts replacement.

Thanks for the advice. Finally got the car back from the repair shop yesterday. The engine misfire during cold starts turned out to be exactly what you described, faulty injectors. Total cost came to 495€ for replacing two injectors and cleaning the entire fuel system. The mechanic walked me through the diagnostic results and showed me the spray pattern tests. Pretty eye-opening to see how badly the old injectors were performing. First cold start this morning was perfect, no more rough idle or stuttering. Engine runs smooth right from startup. Such a relief after dealing with hard starting problems for months. The shop also recommended running injector cleaner every 6 months and sticking to quality fuel stations. Makes sense given how sensitive these modern fuel systems are. Really glad I got this sorted before winter. The fuel delivery issues were getting worse and I was worried about causing permanent engine damage. Thanks again for helping me identify the problem correctly.