Z3 Fuel System Troubleshooting: Stalling & Rough Idle Fix

Hey there! Had a similar issue with my 2005 BMW Z4 last month. The symptoms you're describing match exactly what I experienced, rough running, stalling, and jerking. Turned out to be a faulty wiring connection between the fuel pressure sensor and the ECU, plus some corroded pins in the connector. My tech found that moisture had gotten into the connector housing over time, causing intermittent signal issues. The fix involved replacing the wiring harness section and the connector. While not a major repair in terms of parts, it required some careful diagnostic work to pinpoint the exact problem. The symptoms can mimic other fuel system issues, which is why proper testing is crucial. At first, I also thought it was the sensor itself, but getting the wiring sorted out completely resolved the problems. Car's been running smooth since then. Just make sure whoever looks at it does proper electrical testing before swapping parts.

Thanks for sharing your experience! That's really helpful since it sounds identical to what I'm dealing with. Good to know it might be wiring-related rather than just the sensor. Just curious, do you remember roughly how much you ended up paying for the repair? Also, has everything stayed working properly since the fix, or have you noticed any other quirks pop up? Been a bit paranoid about car repairs lately after getting burned by my last mechanic.

Hey again! Just wanted to follow up, yep, everything's been running perfectly since I got it fixed. The total cost was 95 € for fixing the cable and connector issue. Honestly, it was cheaper than I expected, especially since I initially thought I'd need a whole new fuel pressure sensor. I totally get being paranoid about repairs, been there myself! But this has turned out to be a solid fix. My Z4's running like a charm now, no stalling, no jerking, and the engine's smooth as butter. The check engine light hasn't come back either. The mechanic found that the main issue was actually the defective fuel pressure sensor, along with that dodgy wiring connection I mentioned before. They sorted both problems out and it's made a world of difference. If you're still looking for a fix, definitely get them to check both the sensor and the wiring, sometimes it's not just one or the other. Haven't noticed any other issues pop up since the repair, which is always a good sign. These BMWs can be finicky sometimes, but once you get the right fix, they're usually pretty reliable.

Just got back from the mechanic and wanted to update you! You were right about getting both the wiring and sensor checked. Took it to a new shop that specializes in European cars. They did a thorough diagnostic and found similar issues to what you described. The whole repair came to 120 €, a bit more than yours but still reasonable. They replaced the sensor and fixed some corroded wiring connections. The best part? My Z3's running amazingly now! No more stalling, jerking, or rough idling. The check engine light's gone too. Really glad I asked here first, saved me from potentially wasting money on unnecessary parts. Thanks again for sharing your experience. It's such a relief to have the car running properly again. Looks like I've finally found a trustworthy mechanic too, which is a huge bonus!