BMW 7 Series Injection Troubles: Stalling and Power Loss

Hey there! I had a similar issue with my 2016 BMW 5 series (compared to my previous 3 series). I have some basic car maintenance experience. Those symptoms sound very familiar. I faced almost identical issues, jerking, high fuel consumption, and stalling. In my case, it turned out to be a faulty connection in the fuel injector wiring harness. My mechanic found that one of the connectors was corroded and causing intermittent connection issues. The repair was relatively straightforward, they replaced the wiring harness connection, which cost me around 95 Euro. Before diving into solutions though, could you share: Current mileage on your car? When was your last fuel system service? Is the check engine light on? This info would help confirm if you're dealing with the same problem I had. The symptoms really do match up with what I experienced.

Thanks for chiming in! My 7 has 72302 KM on the clock, and I just had it serviced last month. Actually, the check engine light came on recently, but I haven't had time to get it scanned yet. That's really interesting about the wiring harness, definitely cheaper than I was expecting! Did you notice if replacing it fixed the smoke issue too? I'm starting to lean towards your diagnosis since the symptoms match up so well. Were there any warning signs before the problems got serious that I should watch out for in the future?

Hey again! Glad to help with more details about my experience. You know, the mileage on your 7 series is pretty close to what mine was when I had these issues (I was around 75,000 KM). Actually, about the smoke, yes, replacing the wiring harness did fix that too! The smoke was happening because the faulty connection was causing irregular fuel delivery to the engine. When the connection was intermittent, too much fuel would sometimes get dumped into the engine, causing that smoke on acceleration. Looking back, there were some early warning signs I totally missed. About a month before things got bad, I noticed slightly rough idling, especially when the engine was cold. Also, my fuel economy started gradually getting worse, but I initially blamed it on my driving style. The jerking started very subtly too, just tiny problems at first that were easy to ignore. Since you mentioned your recent service, I'd definitely get that check engine light scanned ASAP. My mechanic told me if I'd caught it earlier, there would have been less strain on the injectors. I got lucky that no serious damage was done. Oh, and here's a tip, after the repair, I started keeping better track of my fuel consumption through a fuel log app. Makes it easier to spot when something's going wrong. Have you noticed any rough idling before the current issues started?

Thanks so much for all this detailed info! That's super helpful, especially about the early warning signs. Come to think of it, I did notice some rough idling a few weeks ago, particularly in the mornings, but didn't think much of it. I feel pretty stupid now for ignoring it! I'll definitely get that check engine light checked out tomorrow, can't believe I've been putting it off. You've actually made me feel a lot better about this whole situation. I was worried I'd be looking at a massive repair bill, but if it's just the wiring harness, that's way more manageable than I feared. That fuel log app suggestion is brilliant, going to download one right now. Honestly, I've been pretty lazy about tracking these things, but this whole experience has been a wake-up call. Really appreciate you taking the time to share your experience. Think I'll start with getting the codes read and then find a good BMW specialist. Going to keep my fingers crossed it's the same issue you had!