No acceleration past 2000rpm / Black smoke

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Andrew H PNG

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Hi everyone,
Have not found a similar issue like this anywhere in this forum except a few posts. But apologies if this was already discussed.

I have a Navara SE 6-Speed manual transmission 2WD and having this issue where I loose speed when reving past 2000rpm > there is no more power and > when depressing the accelerator pedal more, black smoke starts coming out of exhaust. It does that on all gears.

I'm fairly new to the operation of the engine so appreciate some advise on what to look at and what could be causing this.
 
Welcome to the forum!

Black smoke always means that the fuel is partly burning but can't finish the job because it's run out of air. Either there's too much fuel, or not enough air. Doesn't matter if it's petrol or diesel, that part works the same.

Here's the thing though - 2,000rpm is the magic figure (diesel engines) that the ECU refuses to let the engine go past when there's something wrong. It should be displaying an engine check light if it knows what is wrong, but if it's not showing the engine light, it's probably the SCV.

If it can rev beyond 2,000rpm it could be air issues (filter, turbocharger, intercooler, EGR). The turbocharger includes the vac hoses and control solenoid - although if yours is a post 2010 model, the actuator is electronic and may be faulty. Nissan did a recall on these back in 2010/2011 and replaced the electronic actuators.

If you haven't blocked the EGR, it's worth doing (unless there's no EGR emission control requirement in PNG).
 
Hi Old Tony,
Thanks for the welcome ��
Mine is a desiel engine and the 2012 model. So don't think I should be concerned about the recall you mentioned.
As for the engine check light, it does not come on. Will check where the SCV is to see if there is a problem with that.
Some have mentioned it could be the fuel injector but then I'm thinking it couldn't be as when I depress the accelerator, you still have fuel going through and being unburnt giving out the black smoke without resulting in more power.
Might be an air supply issue. I replaced the air cleaner filter about 15,000km ago so don't think I need to replace with new.
The EGR and turbo I am still yet to check.
 
I think it was around your model that had a "soft" hose between the air filter box and the turbocharger. This would collapse on high boost causing a restriction - you couldn't see it standing beside it unless it's on a dyno, because you can't get enough boost developing with the car in neutral.

Have a good look at that hose. If it doesn't feel sturdy, you might consider replacing it.

The SCV is attached to the fuel pump.
 
Hi Rumpig,
Doesn't look like this model had the diesel particulate filter (DPF) as there is no mention of this in the manuals.
Old Tonny,
There is no soft hose between the air filter box and the turbocharger that I can see. I have checked all the hoses to the turbo and they are all fine. Will be checking the SCV soon. Kind of slow in checking things as I usually do not have time in the afternoons when I get back from work or during the weekends.

However, Just a bit of update to what I have done to the truck...
I replaced the fuel filter which was due for replacement 5000km ago (recommendation is to replace every 40,000km for normal driving conditions and 20,000 for severe driving conditions. At the same time as well, add some cleaner for the injectors to the diesel and did a 100km trip. No improvements were noticeable. Maybe might have some improvements with running for a bit more km.
This leads me to checking the suction control valve. Trying to find out what exactly I can do before I do the work. Do not want anything to happen to the truck as I rely heavily on it to get to and from work every morning.
Also checked the DTC for any fault Codes that could point to the problem however it gave me a 0000 which means there are no issues or faults.
Another check that I have read on was to check the pressure release valve of the fuel pump. So will check that and the SCV the same time.

If you have specific instructions or precautions would appreciate it.
 
The SCV is difficult to get to with arthritic hands or mine would have been out this morning. Two 5mm allen key bolts and an electrical connector on the back - I also undid my oil dip stick to move it aside but still couldn't manipulate the electrical connector or the allen key. I have to hand mine to a mechanic to do, it's sad but age does it to you!

Here's a pic. You can just make out the SCV, I've pointed an arrow at one of the allen bolts.

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My SCV was replaced today. Problems are gone. Fuel rail gets up to just over 25,000psi and no complaints from anything. Power restored, confidence returned, Hiluxes are specks in the mirrors once again.
 
Oh wow, that's good to know.
Did you experience the same symptoms like me?
And can you clean the SCV and put it back?
Also, Have seen some videos where they mention to remove and then turn it around and install and see if the problem goes away. And it it doesn't , then replace.
If I need to replace, do I need to know the part number or anything for my specific vehicle or is it the same for all Navara?
 
My symptoms were similar - not identical. I could rev past 2000rpm, but it was quite unstable, like it was trying to hold back - the harder I pressed the accelerator, the more the car lurched when the fuel rail pressure dropped.

That's the thing I think you need to look for - the fuel rail pressure as it's playing up. Mine wouldn't go much over 24,000psi and when it did, it was only for a couple of seconds and then it fell to around 10,000psi (under half). Now it happily hits 25,000psi and stays there (that's the max pressure for these cars, by the way - 1700BAR).

Get a read of your rail pressure and see what's happening with it. The SCV can be cleaned and that'd be the first step - I replaced mine, because I couldn't actually remove the SCV myself (arthritis) so I paid someone to just replace it.

Nissan part number for mine is A6860-VM09A, looks like mine's the short one. There's also a long one - you have to know which one yours is. Wait, I'll take a photo next to a tape measure so it helps.

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Actually tony there is now a universal kit available so you can run the LONGER SCV on the where the short ones where used.

They are much more reliable, more pressure and better regulated..

I've done my SCV so many times, I can do it with my eyes closed .. haha

If some one is chasing a small SCV for their nav, let me know. I have one that has had maybe 200ml pass through it (install, start, turn off, removed)
 
Without having the take the SCV out and measure it is there any way of knowing by year and model if you have a short or long SCV.

I have a 2013 ST, Spain built.
 
I've obviously still got my old SCV which in fairness lasted well over 200,000km (and many of those with near - or more than - 2T behind her). I can't say I'm upset about it.

So in about 160,000km I'll look for one of those longer SCVs!
 
Thanks Old Tony. That really helps in knowing what I need to look for and how to get to it. I will see how I go. I am actually on a business trip so will be working on the truck when I get back and over the Christmas public holidays that is coming up.

From reading through these posts and also other posts, I see that the SCV is a common issue that D40 owners have. Not sure if Nissan have done improvements or have provided a recommendation on what needs to be done to this. Either there is an upgrade to the valve or the whole assembly or if the recommendation is to replace the SCV at a particular interval.
 
So my problem has been solved. Checked all that I could and just yesterday, I gave a good clean to my air cleaner filter and the engine power came back!! It was that simple!
Didn't think it was the air filter as I had changed it about 20,000km ago and got it cleaned by hitting the dust out. But it does look like that was not good enough. Yesterday I dusted it and actually vacuumed the dust out from the dirty side and it actually made a big diffrrence.

Glad I didn't have to replace any parts like the SCV or worst, the turbo charger! But I'm glad I had this issue as now I understand a lot more about the engine and how it works by going through this troubleshooting exercise and checking all the loops and components.

Thanks everyone for the help especially Old Tony and will keep in touch should I have any other issues or can help anyone who is facing the same issue and want some advise on where to start with troubleshooting.

Cheers
 

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