Captiva Fuel System Woes: Stalling & Running Rough

Had a similar issue with my 2006 Chevrolet Epica. Got some experience working on fuel systems after dealing with this problem. The symptoms sound very familiar, mine had rough idling and stalling too. The culprit turned out to be a loose connector on the fuel pressure sensor. The workshop did a full diagnostic scan first, then checked the fuel pressure and connections. Was worried about fuel contamination initially, but the technician found those disconnected cables pretty quick. Total repair cost was 95 Euro, mainly labor for diagnosis and fixing the connection. Much better than having to clean the fuel system or replace components. Before jumping to conclusions though, need some more info about your Captiva: What's the error code showing? Notice any other symptoms besides rough idle? How's it running at higher RPMs? Any unusual noises from the engine? Getting that error code read should be your first step, could save you time and money pinpointing the exact issue in the fuel system or combustion chamber.

Thanks for sharing about your Epica. I checked the error code finally, it's showing P0171, which indicates a lean fuel mixture. The engine runs better at higher RPMs, but still not great. No strange noises, just the rough idle and occasional stalling. Last service was at 115,000 KM where they did basic maintenance but didn't touch the fuel system. Might be time to check the fuel filter since I can't remember the last time it was replaced. The rough running and lean condition could point to restricted fuel flow. I'm hoping it's just a clogged filter and not more serious fuel system issues, given the car's age and mileage (119,069 KM). Will probably get the fuel pressure tested too just to be safe. Given the improved running at higher RPMs, I don't think it's severe fuel contamination, but that last fill-up timing does make me wonder about the fuel quality.

Good call getting that error code checked. P0171 on these engines often points to vacuum leaks rather than fuel quality issues, had the exact same code on my Epica before sorting the sensor connector. But since you're having similar symptoms after a fill-up, it's smart to look at the fuel system too. That rough idle improving at higher RPMs matches what I experienced. On mine, the lean fuel mixture was causing the engine to hunt for idle and occasionally stall. If your filter hasn't been changed since that 115,000 KM service, that's definitely worth checking, these engines can get pretty sensitive to restricted fuel flow as they age. Quick tip from my experience, before replacing parts, have them check the intake for vacuum leaks and verify fuel pressure. My mechanic spotted the connector issue during the pressure test. Would have wasted money on parts otherwise. The wrong fuel or contaminated fuel usually shows different symptoms, typically more engine knock and poor performance across all RPMs. The improved running at higher revs suggests it might be a minor vacuum leak or sensor issue rather than serious fuel system problems. Worth investigating before jumping to fuel contamination conclusions, especially given these models' common vacuum leak points around the intake manifold.

Thanks for the detailed input. After considering the vacuum leak possibility, I did some checking and found a cracked vacuum line near the intake manifold. That would explain the lean condition and why it runs better at higher RPMs. Starting to think the timing with the last fuel fill-up was just coincidence. Going to replace that vacuum line first since it's a cheap fix, then get the fuel pressure tested if the problems continue. The fuel filter replacement can wait until I rule out the vacuum leak, no point spending money on parts I might not need. Though with the car's age, I'll probably do the filter soon anyway as preventive maintenance. Really glad I posted here, would've gone straight to fuel system repairs without checking for vacuum leaks. Will update once I get that line replaced to let others know if it solved the engine's rough running and lean condition.