Strange boost issue

[the godfather]

Vacuum.PNG
My understanding is that if this little tank (actuator) is faulty you get mixed signals going over the place.
If it completely fails you loose all your turbo boost.
Best thing would be to rip one off a mates car and try it on yours (or vicar verse).

[docp1980]

So, I took the car to United Fuel Injection who dynoed it and could not find a problem, except they said my boost gauge was faulty as there's worked fine. I then bought bought a new autometer gauge; same problem still there! I have also re-run the boost line to try and rule this out. Any one with any other ideas? I'm at the point of just re-ordering the complete dawes/needle system again and replacing it!

[threedogs]

Im thinking you have a cheap nasty needle vavle,
they are prone to failing and hard to diagnose.
I brought my needle vavle from Dependable in SA
I take it its a Common rail 3ltr??

[mudski]

So it only happens when it is cold right?
I would be looking for a fracture somewhere, maybe in the little plastic vacuum tank under the IC.
They also have a one way valve in them that can play up occasionally.
I will try and post a picture of the unit.
They are $95.00 from Nissan. I just replaced mine because it was perished.

Those vac tanks are prone to breaking yes but its something you just throw away and by pass anyhow. They're not needed and we removed from the Patrol from about 2002 I think....
To the OP. What type of needle valve are you running? Also, if the maf is faulty, you will see similar issues. A member here had similar issues and it turned out it was the maf the whole time. Plus I have seen happen to other Patrols, including CRD's.

[threedogs]

Pretty sure the OP has a 2005 or later so the vacuum can is not an issue as you say.
Only saying that as he has a scan gauge,

[docp1980]

Needle valve is a top quality Tognella one, bought from Dependable. Patrol is a 2013 CRD, so that vac tank shouldn't be the issue. Based upon the fact that this just happened out of the blue after a year of running fine, I am inclined to go with the faulty MAF sensor suggestions. Does anyone know how much a new MAF is going to set me back? The Patrol is still under warranty, so if I put the boost back to vacuum/ECU control and take it to Nissan would they be able to diagnose the faulty MAF? Thanks heaps for all the suggestions!

[docp1980]

$200 for a genuine Nissan CRD MAF from Nizzbits! Damn! I don't suppose anyone in the Perth area would have a spare MAF I could put in to see if that's the problem?

[mudski]

$200 for a genuine Nissan CRD MAF from Nizzbits! Damn! I don't suppose anyone in the Perth area would have a spare MAF I could put in to see if that's the problem?

$200 i would say that's a direct injection maf. The crd mafs are around $300. Give or take....
If you cantry a maf first that would be ideal.
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[mullet_hunter]

Can u post a vid of your scan gauge in real time? My autometer gauge n ecu talk gauge are both identical for psi readings...
Also what happens with ur boost in standard configeration.. ie hw much boost etc.. hw much valts u getn at maf sensor?..

Heres all the possible problems..

Test intercooler for leaks in bucket of water.. block both ends n preasurerise with bike pump or if you use an air gun be carefull to only feather the trigger...

Reinstall all intercooler hoses..

Double check all vac lines...

Clean/replace maf sensor...



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[the godfather]

Anymore news on this issue? Curious to know what t was.