Nissan Repair Questions? Ask a Mechanic for Answers ASAP
If the vehicle is puffing out black smoke from the exhaust then this would indicate over fuelling. Having the EGR blanked off will not help the equation in the slightest as the EGR in effect recirculates some of what was in the exhaust and reburns it in order to lower emissions.
It appears that you have changed pretty much everything on the vehicle and as long as these are new parts and not second hand then you should pretty much have eliminated all of those! You have also stated that you are changing injectors however I suspect it will not cure the issue!
You haven't said anything about completing a diagnostic code read? Have you done this? Was there any codes? You also haven't mentioned anything about a live data check. Are the readings on the various sensors what you would expect? For over fuelling issues the first ones I would look at are sensors related to temperature so Air Temperature Sensor (this is usually part of the MAF Sensor) and Engine Temperature Sensor. Are these giving the correct readings? If they are showing minus temperatures then the Engine Control Module will compensate by increasing the fuelling for the cold temperature.
It may not be the sensors themselves that are at fault. It could be wiring or it could be the Engine Control Module itself. Check the sensors then the wiring and finally if that's all ok it leaves you with module issues.
Very rarely have any issues with them! Occasionally if the units gets carboned up through short journeys they can stick or more often on vehicles with DPF if the pressure pipes have split and the DPF won't regen then again a bit of carbon build up may occur.
If you had loss of power then you are either looking at an air leak or fuelling issues potentially. Occasionally if the EGR was stuck open then you might get slight loss of power but they usually fail closed!
Quite high mileage then. You have the injectors anyway so if you are going to fit those you can see if it makes any difference. It won't do it any harm at that mileage to have a set anyway! Let me know how you get on after you have fitted them.
I see from your list that you have fitted a turbo. Is this a new unit?
I only ask because it's amazing the amount of people that seem to think fitting second hand parts will work! I think with what I have heard you have covered pretty much all bases.
What does the vehicle drive like?
The only thing I can think that you haven't touched on is Timing Chain. In particular the lower one. Could have jumped a tooth especially at that mileage!
Yes smoking, rattling, poor running.
See how you get on with that. I certainly hope you find something there after replacing so many things!
Do you know where you are at with Timing Chains? If not I can see if I can find some information for you. I would need the VIN number to ensure I get the correct vehicle.
I'll see what I can find for you.
If you go to this website: Nissan B2B and click on the link at the bottom 'IMT Sign Up' you can register as an independent user and view the Electronic Service Manual for your vehicle. This has all of the details with reference to your timing chain along with helpful pictures.