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FelixFahrer

Black Smoke & Engine Cuts: Infiniti QX Fuel System Crisis

Strong exhaust smell

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Engine shuts off by itself

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Poor fuel economy

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Jerking on acceleration

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Unsteady engine

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Loss of engine power

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Stalling while idling

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Check engine light on

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Black smoke from exhaust on acceleration

Hey all, need some advice on my 2012 Infiniti QX (67,724 km). My car's been acting up lately black smoke when I accelerate, engine keeps cutting out, and the check engine light won't go off. It's also jerking when I hit the gas and burning through fuel like crazy. Had a not-so-great experience with my last mechanic, and I'm thinking it might be the fuel level sensor. Has anyone dealt with similar symptoms? Any recommendations for a reliable mechanic who's good with Infinitis? Would really appreciate hearing about your experiences. Thanks!

4 comment(s)


KlaraFahrer

Hey there, I had similar issues with my 2015 Infiniti Q50 last year. The symptoms you're describing sound really familiar I dealt with the black smoke, jerking, and high fuel consumption too. Initially thought it was the fuel sensor, but turned out it was a faulty wiring harness connector near the fuel injection system. Took it to my regular mechanic, and they found several corroded wires in the main engine harness that were causing intermittent connections. This was causing the ECU to get wrong readings and mess up the fuel mixture. The repair involved replacing the whole wiring harness assembly it wasn't a quick fix, took them about two days to complete. It's definitely a serious issue that needs immediate attention since it can cause more damage to your engine if left unrepaired. The black smoke usually means you're running rich (too much fuel), which isn't good for your engine or your wallet. Can't help with mechanic recommendations since we're probably in different areas, but make sure whoever you choose has experience with Infiniti's electrical systems. These problems can be tricky to diagnose if you don't know what you're looking for.

FelixFahrer (Author)

Thanks for sharing your experience! That's really helpful to know about the wiring harness seems like it might be the same issue I'm dealing with. Just curious, do you remember roughly how much you ended up paying for the whole repair? Also, has everything been running smoothly since then, or have you noticed any other issues pop up?

KlaraFahrer

Hey again! Happy to give you an update! Yes, everything's been running perfectly since I got it fixed. Just had the car checked at my mechanic last week actually they confirmed the fuel level sensor malfunction was completely resolved. Turned out it was exactly what we thought a defective wiring harness/plug that needed replacing. The total bill came to 95€ for the repair, which honestly wasn't as bad as I was expecting. My Q50's been running like a dream since then no more black smoke, jerking, or fuel consumption issues. The engine's super smooth now, and I'm getting much better mileage too. It's such a relief when you find the actual problem and get it sorted, isn't it? Especially with these kinds of electrical issues that can be so tricky to diagnose. Really glad I could help point you in the right direction with your QX. Let me know how yours turns out!

FelixFahrer (Author)

Thanks so much for all the info! I actually just got back from the mechanic today. You were spot on about the wiring harness! Took my car to AutoTech Solutions they're certified Infiniti specialists, and wow, what a difference from my last mechanic. The repair was a bit pricier than yours ended up paying 1,200€ total because they had to replace some additional connectors too. But honestly, it's worth every cent. The car's running amazingly now no more black smoke, jerking's completely gone, and my fuel consumption is back to normal. The whole process took about three days because they had to order some specific parts, but they kept me updated throughout. They even showed me the old corroded wiring it was pretty scary to see how bad it had gotten! Really appreciate everyone's help here, especially your detailed experience. It definitely helped me understand what I was dealing with and made me feel more confident about getting it fixed. Guess I've found my new go-to mechanic too! Thanks again!

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