Fiat Doblo Engine Issues: Declining Power, Increased Exhaust Smoke, and Possible Fuel Pump Concerns

Hey there, I completely get what you're saying. Had a similar issue with my 2013 Fiat Ducato diesel a while back. The engine had problems, jerking during acceleration, and the check engine light was a constant annoyance. Did some digging, got my hands dirty and eventually found the culprit - it was a defective wiring harness/plug, not the fuel pump as I initially suspected. The wiring harness was causing an intermittent connection to the fuel pump, messing up the fuel mixture and causing all kinds of havoc. These symptoms you're describing with your Doblo, especially the engine power dip and black smoke, sure sound a lot like what my Ducato was going through. Getting it sorted was no walk in the park. Essentially, the mechanic went through the process of determining that the wiring harness was corroded, replacing it, and ensuring that the plug was functioning as it should be. From a severity perspective it was a pretty serious issue. The defective wiring could've caused a fire under the hood, so I'd highly recommend checking this as soon as possible. It's definitely not something to be shelved. Hope this helps!

Hey, thanks for sharing your story, really appreciate it! Good that you finally found the real culprit. Those symptoms sound pretty identical to what my Doblo's going through at the moment. I've got a feeling it's the same wiring issue rather than the fuel pump itself as I initially thought. Fixing this sounds like a bit of a job, but I can't ignore this any longer, especially now knowing how severe it can get. I'll get onto it ASAP. Out of curiosity, do you remember how much it cost you to get it all sorted out? And how’s your Ducato holding up now? Have you encountered any other problems since you fixed the wiring? Cheers!

Hello again, You're absolutely right. Can't take a serious thing like this lightly. In terms of cost, sorting out that misbehaving wiring harness set me back 95 Euro. Worth every penny considering the potential hazard it posed. Now, about your second question on how my Ducato's been doing since then. Let me tell you, touch wood, it's running like a dream again. When I was dealing with this issue, I was kind of fixated that it was the fuel pump acting up but turns out it was fine. Got it checked up by the mechanic when the wiring was fixed and, thankfully, no issues there. Hope this puts your mind at ease a bit and gives you a good head start in resolving your Doblo's issue. Take care!

Hey, thanks a ton for enlightening me with all these details. It’s good to hear that the repair seems to be financially manageable. I got worried thinking about the cost of a potential fuel pump replacement! And now hearing how smoothly your Ducato's running post-fix, it's encouraging. Given all you've said, I’m optimistic and fingers crossed, hopefully my Doblo will be back to its old self soon. I'm planning to make a visit to the mechanic tomorrow. Cheers for the advice! Take care too, and here’s hoping we don't meet any more unexpected problems with our Fiats!