FX Diesel Engine Symptoms: QDC Reset Guide Needed

I had similar issues with my 2014 Infiniti QX70d (basically same engine family). The symptoms you're describing are spot on with what I experienced rough idle, power loss, and excessive fuel consumption. In my case, it turned out to be a faulty fuel injector. When I took it to the dealer, they ran diagnostics and found that one injector was misfiring. They had to replace the injector and do a QDC reset afterward. It was definitely a serious issue that needed immediate attention because bad injectors can cause more damage if left unchecked. The process took about two days at the shop. They had to order the part and then reprogram the ECU after installation. The QDC reset was necessary to calibrate the new injector with the engine management system. After the fix, the engine ran smooth as new. No more shaking, power loss, or excessive fuel consumption. These symptoms shouldn't be ignored I'd recommend getting it checked at an authorized Infiniti dealer since they have the proper diagnostic tools for these engines.

Thanks for sharing your experience this sounds exactly like what I'm dealing with! Really helpful to know about the injector being the culprit. My FX is running so much better now after getting it fixed at the dealer, just like you suggested. Do you remember roughly how much you ended up paying for the whole job? Also, has everything been running smoothly since then, or have you had any other issues pop up? Would love to know what to expect down the road.

Hey there! Glad to hear you got your FX sorted out these engines can be tricky sometimes! Yeah, I remember the costs pretty clearly because it was a significant repair. The total came to 515€ for fixing the defective injector, which included the QDC reset they had to do afterward. Honestly, while it wasn't cheap, it was worth every penny because the car's been running like a dream since then. Since getting that injector replaced and having the QDC reset done, I haven't had any similar issues pop up. My QX70d's been performing great no more rough running, no power loss, nothing. It's been about two years now, and the engine's still running smooth as silk. Fuel consumption is back to normal too. Just make sure you keep up with regular maintenance, and you shouldn't see this problem again. These engines are actually pretty reliable once you sort out any initial issues. If you notice anything unusual though, don't wait get it checked out early before it turns into a bigger problem. Has your fuel economy improved since the repair? I noticed a huge difference in mine right after the fix.

Thanks for the follow-up! Yeah, I hear you about the costs I actually ended up paying around 485€ at my dealer, so pretty close to what you paid. Guess that's just what these repairs cost. Really good to know you haven't had any issues for two years now. That's super reassuring! And yes, the fuel economy has improved dramatically I'm getting way better mileage now. It's like driving a different car! I just wanted to update on how my repair went too. The mechanic was spot on it was indeed a faulty injector. They got it sorted in about a day and a half. The whole experience was actually pretty smooth, way better than my previous mechanic. They even gave me a full rundown of what they did and some maintenance tips. Been about two weeks since the fix now, and everything's running perfectly. No more shaking, no power loss, and the engine's quiet as can be. Definitely learned my lesson about not waiting too long when these issues pop up! Thanks again for all your help. It really made me feel better knowing someone else went through the same thing and got it sorted. Here's hoping both our cars keep running smoothly!