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Discussion Starter · #1 ·
Hi Guys,

I have had my navara diagnosed for black smoke and weak performance.

Nissan found the scv to fluxuate from 26 to 34 mpa (should be 40 mpa) They advised to:
Replace scv which i have done without sucess
Check fuel pump timing as the car "runs on" when you turn the ignition off.

When I went to check the fuel pump timing I found there is two slots where the 6mm locking pin fits into the pump? see photos.

Is it possible that the previous owner have had the timing set and used the wrong pin hole resulting in the pump being set one cog off?

Is there a other way to check that the pump is set correclty? or is the only way to pull the pump out and reinstall?

Cheers
 

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A couple of thoughts.

Did you reset the fuel pump using the throttle pedal method when you changed the scv? If not the new one will not work.

Do you have any fault codes showing? (I assume you have some type of code reader)

The engine is prevented from running on by a throttle flap just before the intake manifold. Is that connected and does it operate when you shut down? ( You will need to take the hose off it to see)

Fuel pump, yes, it could have been assembled incorrectly. However it would never have run properly that being the case. So I think it is highly unlikely that this would be your problem.
 

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Discussion Starter · #3 ·
No unfortunatley I did not do the reset... bad mistake..
Ill check the throttle, i acutally never noticed it running-on but nissan noted that..
Alright, ill put everything back togheter and hope for the reset of the scv being the issue.

When you say not run properly with injector pump one cog out, it wouldnt hold idle and stall etc?

The car starts right away and is sort of driveable, it just feels a bit sluggish and blows a bit of smoke (not too much, seen way worse)
 

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Hi Perrka, since many years modern diesel engines (as also Nissan Navaras) use the common rail technology. This means that there is no need for any "fuel pump timing" because the fuel pump is degraded for only producing enough fuel pressure in the common rail and not worrying when to let it into the cylinder/combustion chamber. This job was trusted to the injectors, sensors and the ECU. That said the (wrong) timing issue can only happen in two ways: 1. Mechanically-the two timing chains are/were not installed correctly, 2. Electronically-the two sensors for the cam- and crankshaft position are malfunctioning. If your problem was to be number 1, you wouldn't be able to drive your car without destroying the engine in a second. If it is number 2, the diagnosis is simple - when the car is running, disconnect one of the two sensors and when the engine does not stop, you found the problem (DISCLAIMER-Do so at your own risk!). It would also be beneficiary to know when the timing chains have been replaced, how many km do they have on them? It could also be the case, that they are stretched but the sensors are ok. The injectors could also be a part of the problem you are facing. When was the last time that they were checked? They should be every 50k km.
 

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Discussion Starter · #6 ·
Alright seems strange to me that Nissan would advise on wrong injection timing reading the above. Also seems strange that there is no need to time the injection pump when there is a locking pin on the injection pump? But YD25.com.au said the same thing as you - no need to time the injection pump)
My theory was that cam and crank is set correctly but the injection is off.
How would disconnecting cam and crank destroy my engine? Fuel injection would potentially happen at the wrong time without cam/crank read?

Not sure when or if the chain has been replaced or checked. I’ll buy the tools required to check the chain, I guess this is a overall good thing to do every time you take the chain cover off.
 

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Discussion Starter · #8 ·
Tried restetting the scv/fuel pump through the pedal procedure, no stored codes and no success.
Checked my cam/crank timing and it also looks good.
When disconnecting the camshaft sensor there is no smoke, however there is also no boost. Same goes for the Maf sensor.
Intake flap operates as it should.

It only seems to smoke under load (uphill) or at high revs/boost. I feel like Im left with either a faulty injector pump or bad injectors.

When Nissan found the scv to fluxuate from 26 to 34 mpa does this mean that the injectors does not get enough pressure?

Some kind of sickness that YD25s run rich after getting a lot of kilometers? Litterly every second navara I see have this kind of behaviour to some degree...? Tuning?
 

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Discussion Starter · #9 ·
To add to this further, this car has been overheating and I have replaced the cylinder head and head gasket.
In this video he explains that the oil sweep ring can become contaminated so the freeze from overheating/not chaning oil.

I havent followed the oil stick enough to see if its actually taking oil or if its overfueling.

Just pulling all strings I can to get to the bottom of this fault.
 

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1. If you disconnect the cam sensor or MAF the engine runs on a default setting, so will still run.
2. There are many things that can cause smoking. Dirty MAF, dirty air filter, worn boost control solenoid and dirty injectors are by far and away the most common. Something a faulty egr system too. Turbo failures are rare, but can cause it. I've not often heard of a failed fuel pump, they seem reliable.
3. 10 to 15 year old Navaras are often smokey, as are many diesels. Mostly for the reasons above. Actually the Navara is very sensitive to a dirty fuel filter, an item very often ignored as part of a service.
4. SCV. In this engine a worn SCV always results in stalling when the engine is worn. If it has worn beyond that you will get a 0089 fault code.
5. Fuel pressure. Assuming you have a code reader you can check the fuel pressure. Fluctuating pressures can be the SCV, poor fuel supply via the filter, worn injectors, a leaking fuel pressure relief valve or a failing fuel pump.
6. This engine does vent the crankcase into the intake pipes, so always there is oil in the intake. That oil is burnt in combustion but not enough to cause smoking. Some people swear by catch cans, not sure they do much apart from keeping the intake clean.

I think from previous threads you sorted the boost control solenoid out (and put the right turbo on) which is the main culprit for serious smoke.

I agree that your problem now could either be the fuel pump or injectors. Getting the injectors cleaned and tested would be my suggestion, especially since you said the engine overheated. (Injectors don't like overheating)
 

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Something I remind myself of, back in say 2004 the average pickup/ute produced around 100bhp/75kw. Great for a landscaper or farmer as he really didn't need to keep up with the traffic and wanted something that would just get from A to B.
The Navara/Pathfinder produced 170bhp/130kw. A massive difference which meant that you could drive it like a car, and so far ahead of the other manufacturers. The trade off- it needs looking after!
 

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Discussion Starter · #15 ·
More things that can go wrong now compared to then I guess..

I can see how the injectors would not like the heat.. I have been struggling to get glow plugs out from overheated engines, never reflected over the injectors. I guess if I’m lucky it’s just the injector nozzles and she’ll be right. Or is it likely other parts of the injector is damaged?
 

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You may have done so but it's worth asking...
Have you checked the very very simple stuff already, as Landmann (who has helped me through my own fuel pump issues) is right in saying the engine is very sensitive to fuel filter issues - the pump's module is fuel cooled.

Had the same issues as you on my second pump. The smoke was so bad I ended up with people behind me on the motorway flashing me. A new, quality, fuel filter and a few tanks of premium diesel with redex injector cleaner (at about four times the recommended dilution!) and it's running better than ever now.

As you've had the head off it could still be anything mentioned so far, might as well check the really cheap stuff before you start throwing parts at it.
 

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Discussion Starter · #18 ·
I normally just bypass the fuel filter when troubleshooting, but not sure if that’s the right way of doing it?
As you are saying premium diesel and additives are very cheap I’ll give it a go as I’m waiting on getting the injectors looked at.

another thing I have noticed is that after replacing the scv the car has started to struggle to hold idle, it’s not a lot but enough to notice if you listen close enough.

I wish I had a scanner that could read engine load and injector readings like injector compensation. I have a few Navaras with this issue, in fact pretty much all of them blows smoke to some degree.

I have another thread about this and it sounds like Nissan consult is the only way to go.
 

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Discussion Starter · #19 ·
Read on another thread that the Autel AP200 can do injector coding on Navaras so Ill give this one a crack hoping it can show live data on the injectors as well. Fingers crossed
 

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I belive it's a Bosch VP44 pump you're dealing with?
Pull the diesel return line from the pump (not with the engine running) and see if the fuel coming out is clean diesel or if it's black and contaminated with oil.
Just a quick job to see if you you're pump is knackered.
 
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