Trouble with engine

[TomNissanNav]

Hey guys,
I have a 2010 nissan navara yd25. I am having a bit of trouble with my engine. It was doing that pull back on power when under load so i pulled out the fuel pressure reg and gave it a clean bit it made it worse to the point that it became hard to start and has like no power under acceleration and also blowing white smoke.
About 2 years ago i got the head redone because the coolant and oil were mixing.
I took it to my mechanic because i was unsure on how to proceed. We tried some sensors but still was the same. What should i look into next.

 

[Old.Tony]

White smoke is excessive fuel (or dramatically insufficient air). Either would cause both symptoms (smoke and power loss).

The difficulty in starting makes me wonder if there's a blockage in the air intake. Not a failed turbo - the turbocharger isn't spinning during a normal engine start and should have no effect at all. But something caught in the air intake (eg a bird in the snorkel - it's happened before) or a badly blocked intercooler could do this.

If it's an auto then there's a possibility that the white smoke is caused by an attempted regen of the DPF, but the car should start easily (because it doesn't try to regen during a start, only once the engine warms up) so I doubt it's a DPF sensor issue.

What I'd do:

1) Throw a bottle of injector cleaner in the tank straight away. Liqui Moly Fuel System Treatment is my go-to for this.

2) Pull the intercooler and wash its insides with petrol. E10 is fine, using 98 won't make a difference here the fuel is being used as a solvent.

3) Ensure that the air filter is clean and nothing seems to be blocking the box (like a bunch of leaves or mud or something in the bottom of the air filter box)

4) Get some electrical contact cleaner (or MAFS cleaner, it's the same stuff) and remove the MAFS and spray this into the small hole in the end (do not ever put anything solid into the hole).

 

[tweak'e]

White smoke is excessive fuel (or dramatically insufficient air). Either would cause both symptoms (smoke and power loss).

sorry but no. excessive fuel or lack of air is black smoke.
white smoke is evaporating diesel, typically from bad timing or injecting so poorly its not burning and its pumping raw diesel out the exhaust. it also can be evaporating engine oil, ie failed turbo, but can have a hint of blue to it.

in this case its more than likely low injection pressure from playing with the pressure valve. tho not sure why ecu is letting it run at that low pressure. unless fuel pressure sensor is faulty.

 

[Old.Tony]

sorry but no. excessive fuel or lack of air is black smoke.
white smoke is evaporating diesel, typically from bad timing or injecting so poorly its not burning and its pumping raw diesel out the exhaust. it also can be evaporating engine oil, ie failed turbo, but can have a hint of blue to it.

in this case its more than likely low injection pressure from playing with the pressure valve. tho not sure why ecu is letting it run at that low pressure. unless fuel pressure sensor is faulty.

I had a case of the white smoke a few years back, my DPF was trying to regen constantly (and excessively, you could smell the raw diesel and it wasn't nice). Nothing fixed that until I got the new sensors from Auggie (this thread). New sensors and the white smoke stopped.

Also had a white smoke problem with my Jaguar (petrol 5.3L V12) when its injectors weren't closing properly. Bloody thing left clouds of it everywhere, it was embarrassing! Mechanic had the injectors cleaned (twice) and then they started behaving. I don't think that's the issue here.

 

[tweak'e]

I had a case of the white smoke a few years back, my DPF was trying to regen constantly (and excessively, you could smell the raw diesel and it wasn't nice). Nothing fixed that until I got the new sensors from Auggie (this thread). New sensors and the white smoke stopped.

yes, because to regen its pumping fuel through the exhaust stroke into the cat which wasn't hot enough to burn it (some manufactures use an injector in the exhaust instead). so it evaporated the fuel making white smoke. see it a lot when people cut out their cat.
when you putting excess fuel into the combustion stroke its burning it badly (not enough air) making black smoke.

 

[Old.Tony]

yes, because to regen its pumping fuel through the exhaust stroke into the cat which wasn't hot enough to burn it (some manufactures use an injector in the exhaust instead). so it evaporated the fuel making white smoke. see it a lot when people cut out their cat.
when you putting excess fuel into the combustion stroke its burning it badly (not enough air) making black smoke.

Nissan did it too, I think there's at least a few V9X engines out there with a 7th injector.

 

[pistol-W]

White smoke is excessive fuel (or dramatically insufficient air). Either would cause both symptoms (smoke and power loss).

The difficulty in starting makes me wonder if there's a blockage in the air intake. Not a failed turbo - the turbocharger isn't spinning during a normal engine start and should have no effect at all. But something caught in the air intake (eg a bird in the snorkel - it's happened before) or a badly blocked intercooler could do this.

If it's an auto then there's a possibility that the white smoke is caused by an attempted regen of the DPF, but the car should start easily (because it doesn't try to regen during a start, only once the engine warms up) so I doubt it's a DPF sensor issue.

What I'd do:

1) Throw a bottle of injector cleaner in the tank straight away. Liqui Moly Fuel System Treatment is my go-to for this.

2) Pull the intercooler and wash its insides with petrol. E10 is fine, using 98 won't make a difference here the fuel is being used as a solvent.

3) Ensure that the air filter is clean and nothing seems to be blocking the box (like a bunch of leaves or mud or something in the bottom of the air filter box)

4) Get some electrical contact cleaner (or MAFS cleaner, it's the same stuff) and remove the MAFS and spray this into the small hole in the end (do not ever put anything solid into the hole).

 

[pistol-W]

I was away for a couple of days...

 

[TomNissanNav]

thanks guys i will look into it all and get back to you