Crafter Diesel Stalling: Likely Fuel System Issues

Had similar symptoms on a 2013 VW Transporter TDI. The engine stalling at idle turned out to be more than just fuel quality issues. After thorough diagnosis, the problem was traced to corroded wiring connections at the fuel pump control module. The check engine light was triggering due to inconsistent fuel pressure readings caused by the faulty connections. While fuel contamination can cause similar symptoms, in this case cleaning the entire fuel system and replacing the fuel filter did not resolve the issue. The fix required removing the fuel pump module, cleaning all electrical contacts, and replacing damaged wiring connectors. This was a serious repair that needed specialized diagnostic equipment to properly identify. Your symptoms strongly suggest checking the electrical connections at the fuel pump first, especially after a questionable repair job. Engine knock and stalling can sometimes be misdiagnosed as wrong fuel when the root cause is electrical. Would recommend having a certified shop perform proper diagnostics rather than starting with fuel additives. The faulty connections can cause permanent damage to the fuel pump if left unaddressed.

Thanks for sharing your experience with the Transporter electrical issues. Your description matches what I am dealing with on my Crafter. The stalling symptoms are nearly identical. I had not considered checking the wiring connections at the fuel pump but that makes perfect sense, especially after that questionable service visit. The combustion chamber misfires and rough idle definitely point toward fuel delivery problems. Do you remember roughly what the repair ended up costing? Also curious if you have had any recurring issues since getting it fixed? Just want to get an idea of what I might be looking at before heading to the shop.

After resolving the wiring issue on my Transporter, the problem never came back. The stalling completely stopped once they corrected the fuel mixture by fixing the cable connections at the pump module. Total repair cost was 95€, which covered diagnosing and repairing the defective plug connections. The wrong fuel composition readings were causing the computer to adjust incorrectly, leading to those combustion chamber misfires you mentioned. Once they restored proper electrical contact at the pump module, the engine ran smoothly again with normal fuel pressure. The relatively low repair cost was worth it to prevent potential permanent damage to the fuel pump. An unresolved electrical issue can end up destroying the pump, which would be much more expensive to replace. Make sure to have them thoroughly check all the wiring and connections while they have it apart. Poor connections can corrode over time and create similar issues again if not properly cleaned and sealed.

I finally got the Crafter diagnosed and fixed last week. Took it to a certified diesel specialist after reading about the electrical issues mentioned here. Glad I did, because it turned out the previous mechanic had damaged some wiring while doing unrelated work. The engine knock and stalling were exactly due to corroded connections at the fuel pump module, just as suggested. The poor fuel pressure readings were throwing off the entire fuel economy and causing those combustion chamber misfires. Total repair came to 180€ including diagnostics, cleaning all connections, and replacing two damaged wiring connectors. The technician also checked the fuel quality and cleaned the fuel system while it was in, just to be thorough. Been running perfectly for the past week, no more stalling, no check engine light, and the idle is completely smooth again. Definitely worth getting it properly diagnosed instead of just trying fuel additives like I initially planned. Thanks for pointing me in the right direction with the electrical issue suggestion. Saved me from potentially much costlier fuel pump damage.