VW Crafter Lean Running Issues & Power Loss Fixed

Having some experience with diesel engines, I encountered a very similar issue with my VW Transporter 2010 diesel. The symptoms you describe match exactly what I experienced, rough running, power loss, and jerking during acceleration with the check engine light illuminated. After diagnostic testing, it turned out one of the fuel injectors was faulty, causing irregular fuel delivery and affecting the air-fuel ratio. The repair involved replacing the defective injector, which cost 515€ including parts and labor. The workshop did a thorough diagnostic first to pinpoint the exact injector that was malfunctioning. Before jumping to conclusions though, could you share: Current mileage on your Crafter, Any recent maintenance performed, Whether you notice blue or black smoke from exhaust, If the problem occurs more during cold starts, Whether fuel consumption has increased This would help determine if your issue is similar to what I experienced. The symptoms can also point to other components like the EGR valve or intake manifold, so getting these details would help narrow down the cause. Consider having a professional diagnostic done. Modern diesel injection systems are complex, and proper testing equipment is needed to accurately identify which injector might be failing.

Thanks for the detailed response. My Crafter has 177283KM on the odometer. The symptoms match exactly what you described with your Transporter. I do notice black smoke, especially during acceleration, and fuel consumption has increased by about 15% in the last month. The throttle body was cleaned during the last service 3 months ago, but the issues started appearing recently. I will get it checked for faulty fuel injectors as you suggested. The oxygen sensor readings from my OBD scanner are also fluctuating wildly, which could indicate a related problem. Based on your experience, would you recommend replacing all injectors if one is found faulty, or just the problematic one?

Thanks for providing those additional details. On my Transporter, I initially only replaced the faulty injector, but ended up replacing all of them within the next 6 months as they started failing one by one. Given your mileage and symptoms, particularly the black smoke and increased fuel consumption, I would strongly recommend replacing all injectors as a set. The fluctuating oxygen sensor readings combined with the black smoke typically indicate incomplete fuel combustion. While cleaning the throttle body was good preventive maintenance, the underlying issue seems more related to the fuel delivery system. The complete injector set replacement on my van cost about 1850€, but it resolved all performance issues and actually improved fuel economy. Make sure the workshop also checks the EGR valve and intake manifold while they are working on it, as carbon deposits often build up in these areas and can contribute to rough running. In my case, doing all injectors at once saved money in the long run and prevented multiple workshop visits. Just ensure you use OEM or high-quality aftermarket injectors, as cheaper alternatives often lead to problems down the line.

Thanks for your helpful input about the injector replacement. The black smoke and fluctuating oxygen sensor readings definitely point toward fuel delivery issues. I just scheduled a diagnostic appointment for next week to have the fuel injectors tested. The 1850€ cost for a complete injector set replacement is actually lower than I expected. Given the high mileage on my Crafter and knowing that you ended up replacing all injectors anyway, I think I will go ahead with replacing the complete set if the diagnostic confirms injector problems. Better to fix everything properly once than deal with repeated issues. I will also have them inspect the mass air flow sensor and EGR valve while they are at it. The check engine light and rough running are really concerning, and I want to address all potential causes. I appreciate the advice about sticking with OEM parts, definitely not worth risking cheaper alternatives when it comes to the fuel system. I will update once I get the diagnostic results and repairs completed. This has been really helpful in understanding what to expect and how to approach the repair.