Alfa Brera: Power Loss & Fuel Issues Signal Injector Woes

I had a very similar issue with my Alfa 159 2.4 JTD from 2008. Having some experience with diesel engines, I first suspected fuel delivery problems based on those symptoms. The power loss and increased fuel consumption turned out to be related to a faulty wiring connection at the fuel pressure sensor. The workshop diagnosed it through their diagnostic system. The repair involved replacing the damaged cable and connector assembly, costing 95 Euro in total. The symptoms you describe, especially the stalling at idle and power issues, match what I experienced. These diesel engines are quite sensitive to fuel pressure irregularities, which can cause both performance problems and excessive fuel consumption. Before suggesting more specific solutions, could you provide: Build year of your Brera, Current mileage, Any engine warning lights showing, When was the last fuel filter maintenance done, Does the smoke color appear black or blue This information would help determine if your issue is similar to what I encountered or if it might be related to other common diesel engine problems in these models.

Last serviced in March, current mileage 114190 KM. Thanks for the detailed response on the fuel pressure sensor. The warning light started flashing about 2 weeks ago, showing a general engine warning. The smoke appears distinctly black, especially under load. The fuel filter was changed during the last major service about 15000 KM ago. Speaking to others privately, several have mentioned similar power problems with the JTD engine could be related to the fuel injectors. Would be interested in your thoughts on this before I commit to workshop time, especially given the symptoms match so closely with your experience.

Thanks for providing those details. In my case with the 159, I initially also suspected injector issues given the similar symptoms. However, after the fuel pressure sensor fix didnt fully resolve the problems, further testing revealed two faulty injectors that needed replacement. The black smoke combined with power loss definitely points toward a fuel system issue, either air getting into the system or incorrect fuel delivery timing. Given the mileage and age of these JTD engines, injector wear is a common problem. In my car, replacing the injectors resolved: The excessive fuel consumption, Power loss during acceleration, Black smoke issues, Rough idle problems The full repair included: Fuel injector replacement (2 units), System cleaning and calibration, New seals and washers Total cost was around 890 Euro but the improvement in performance and fuel economy made it worthwhile. The engine warning light hasnt returned since. Given your symptoms match what I experienced almost exactly, and considering the service history you shared, Id recommend getting the injectors tested. These JTD engines are known to need injector work around the 100000-120000 KM mark.

Thanks for all this detailed information. After comparing my symptoms with your experience, I'm convinced the injectors need proper inspection. Your repair cost breakdown helps set realistic expectations for the work ahead. The matching symptoms, especially the black smoke, power loss, and fuel consumption issues, along with my car being in that critical mileage range make a strong case for injector problems. Considering this is a known issue with these diesel engines, I will book the workshop time and specifically request injector testing. The air intake and fuel delivery systems clearly need professional diagnosis. Given your successful repair outcome and the similar pattern of issues, I feel more confident about the potential fix, even though it represents a significant maintenance cost. I will update once I have the workshop results and know whether it was indeed the injectors causing these power and fuel efficiency problems. At least I can go in with a clear idea of what to expect both in terms of the likely repair needs and costs.