VW Crafter Rough Running and Stalling: Fuel System Alert

Having experienced similar symptoms with a VW Transporter T5 2010 diesel, this sounds like a faulty injector issue. The rough running, stalling, and jerking during acceleration typically indicate a rich mixture problem, which in these engines often traces back to a defective injection valve. The intake manifold on my Transporter started showing similar symptoms at 68000km. After proper diagnosis, it turned out one injector was stuck partially open, causing uneven fuel distribution. The check engine light was triggered by the oxygen sensor detecting irregular exhaust composition. This is indeed a serious issue that requires immediate attention, as continued driving can damage the catalytic converter due to excess fuel. The repair involved removing and testing all injectors, with one requiring replacement. The job needs specialized diagnostic equipment to properly code the new injector to the engine management system. Key indicators that helped confirm the diagnosis: Black smoke from exhaust, Rough idle particularly when cold, Significant power loss, Uneven engine sound, Failed sensor readings Recommend finding a workshop with specific VW commercial vehicle certification and proper diagnostic tools. This is not a job for a general repair shop.

Thanks for sharing your experience with the T5. My Crafter had similar issues last year. After testing, it turned out the mass airflow sensor was sending incorrect readings to the ECU, messing up the air-fuel ratio. The throttle body was also pretty gunked up, which made the idle problems even worse. Can you remember what the total repair cost was in your case? Just curious since these issues can get expensive. Has everything been running smoothly since the injector replacement?

Good news, after replacing the faulty injector, my T5 has been running perfectly for over a year now. The fuel injection system is working as intended, with no more check engine light issues or mixture preparation errors. The repair cost came to 515€ for the complete job, including diagnostic work and coding the new injector to the ECU. The symptoms you mentioned with your mass airflow sensor definitely align with what I experienced. The air-fuel ratio being off causes similar problems. Getting the proper diagnosis and fix is crucial, in my case, the oxygen sensor readings were all over the place until the new injector was installed. A proper repair shop will have the right diagnostic equipment to pinpoint whether its a sensor issue or mechanical problem affecting the fuel delivery. When they fix it right the first time, these engines run reliably for many years. The key is finding someone who knows these VW commercial engines well.

The mechanic visit finally solved my ongoing issues. After seeing your response about injectors, I had it properly diagnosed at a VW specialist workshop. Turns out my mass airflow sensor was actually fine, the main problem was two faulty spark plugs and a partially clogged fuel injection system. The total repair came to 380€, including cleaning the entire fuel system and replacing all spark plugs as a set. The intake manifold also needed a thorough cleaning, which they included in the service. Much better than the 800€ quote I got from my previous mechanic for unnecessary parts replacement. The engine now runs smooth as new, no more stalling, jerking, or power loss. No check engine light either. Really glad I followed the advice to find a proper VW specialist. Would have saved time and money going there first instead of the general repair shop that couldn't properly diagnose the issue.