Turbo/boost issues

[Brad20v]

Hello everyone. R51 2012 Electronic turbo actuator
Ok so over the last couple of weeks I have noticed an issue where my car has no power down low, turns out the little lever on the actuator wasn't rising when engine started, it would jump back to position if stalled up or driven,you can feel it suddenly make boost at 2500rpm, anyway it's a replacement turbo I just installed the factory Hella control box, time will tell if that has fixed anything. Also on my torque app under load /power, the boost reads 21.9 then then suddenly -29in Hg vacuum, goes back and forth. Fuel rail pressure doesn't not drop its around 22000 to 24000 psi. Any ideas what could cause this? I was thinking possibly the boost valve on the intercooler, if I unplug it, I get the same -29 vacuum reading but also throws a boost code, which doesn't happen when driving.
Thanks

 

[Old.Tony]

Sounds like it might be overboosting every now and again. I have a Tillix valve (vacuum control in mine) and if I was trying to push the boost a little higher and got it just a little too high, I had the exact same symptoms.

And on one occasion - at night climbing a hill on the Putty Rd - I popped the hose off the intake manifold. In the dark I refitted the hose, backed the Tillix valve off half a turn just to be safe (better lower boost than none at all) and we continued.

 

[Brad20v]

Hello Old Tony
Do they have a boost cut out? I'm pretty sure it's always run that boost , especially with my chip in (which currently isn't).
The little link from wastegate to electronic actuator look slightly different lengths maybe I try swap them boost may go down or up.
Thanks

 

[Brad20v]

Thing is nothing has changed on the car for nearly 2 years this turbo has been fitted, it has 3" exhaust plazmaman intercooler and pipework.

 

[Old.Tony]

I can't explain the "negative" figures any better. Mine does the exact same thing when I have my Tillix valve adjusted too high. If I leave it that way, eventually the ECU chucks a wobbly and I get an overboost error in the ECU, so either something has increased the boost (in my case, my adjustment of the valve, but in your case, perhaps the electronic actuator is one that wasn't replaced by Nissan during a recall - see below) or the boost sensor is misreading the pressure through either a fault (really rare) or debris inhibiting the sensor (quite possible).

The Navaras of 2013 and later (remembering that as an R51, you had newer tech than the "agricultural" utes so it gets the new tech earlier) changed to electronic actuators on their turbos and these things had problems that were bad enough to cause Nissan to recall the cars to have this exact component replaced.

You might want to see if there's any indication that yours has had this recall dealt with (or even if it was needed). A call to Nissan with your VIN handy would answer the question fairly quickly.