VW Crafter Diesel Misfire & Power Loss: Common Fixes

I had a very similar issue with my 2015 VW Transporter diesel last year. As someone with moderate experience working on diesel engines, these symptoms immediately pointed to fuel delivery problems. The rough idle and check engine light, combined with power loss and combustion misfire, strongly suggested a fuel injector issue. After diagnostic testing, it turned out one of the fuel injectors was defective and needed replacement. The repair involved: Complete diagnostic scan, Fuel injector removal and testing, Replacement of the faulty injector, System reprogramming, Test drive verification Total cost came to 515€, including parts and labor. The repair resolved all symptoms, the engine now runs smoothly, no more check engine light, and power delivery is back to normal. Before suggesting specific solutions for your Crafter, could you provide: Current mileage, Maintenance history, especially fuel system services, Whether the problem appeared suddenly or developed gradually, Any unusual sounds or smoke from the exhaust, Fuel type and quality used This information would help determine if your issue is similar to what I experienced with my Transporter.

Last service was done at 59000KM and everything checked out fine. The problem started gradually over the past month. No strange sounds from the exhaust, but noticed black smoke occasionally during acceleration. Been using standard diesel fuel from regular stations. The throttle response has definitely gotten worse since the problem started. Rough idle is most noticeable when the engine is cold. The check engine light started flashing intermittently before staying on permanently. Getting it to a shop next week, but wanted to confirm if fuel injector testing should be the first step based on these symptoms. Would a faulty fuel pump cause similar issues? Did your repair also include checking the high-pressure fuel system? Want to make sure the shop covers all potential causes when they diagnose it.

Based on those additional details, your symptoms sound nearly identical to what I experienced. The black smoke during acceleration combined with declining throttle response strongly suggests fuel delivery problems, just like my Transporter had. In my case, the shop did perform a complete high-pressure fuel system check before isolating the faulty injector. While a failing fuel pump can cause similar symptoms, the black smoke during acceleration is more characteristic of injector problems. My repair included pressure testing of the entire fuel system to rule out pump issues. My fuel injector problems also started with intermittent check engine warnings before becoming constant. The rough idle was similarly worse during cold starts, which is a classic sign of injector problems in these VW diesels. When my shop diagnosed the issue, they found carbon buildup inside the injector was disrupting the spray pattern, leading to incomplete combustion and those misfire codes. The black smoke you mentioned often indicates poor fuel atomization from a worn or clogged injector. Make sure your shop performs: Fuel pressure testing at the rail, Individual injector diagnostic tests, Injector spray pattern analysis, System leak testing, Full computer diagnostic scan After my repair, the combustion misfire codes cleared completely and the rough idle disappeared. The throttle response returned to normal almost immediately.

Thanks for the detailed information. Just gave the shop a call and scheduled comprehensive fuel system testing next week. Will make sure they check both the injectors and high-pressure system as you suggested. Your experience really helps set my expectations. The black smoke during acceleration and rough idle symptoms matching your case makes me feel more confident about the likely fuel injector diagnosis. Good to know the repair resolved all issues in your situation. Will request they perform all those diagnostic steps you listed. The spray pattern analysis seems particularly important given the similar symptoms. My check engine light behavior following the same pattern as yours, going from intermittent to constant, further supports this being injector-related. The throttle response issues and cold start problems are definitely getting worse, so addressing it now before any additional damage occurs seems smart. Will update once I get the official diagnosis and repair completed. One final question, did you have any residual issues after the repair was done? Just want to know if I should expect everything to clear up immediately like in your case.