[pvtschultz]

Is it able to build ~14 psi under WOT without the tune?

My experience with the '11-'12 Eco's is that the solenoid valves that control the recirculating valves (BOV's) will leak vacuum/pressure causing the BOV to not seat. Usually this is a low to part throttle issue since manifold pressure should be holding the valve shut under boost. Here's a link to a thread that I started regarding the issue.
http://www.f150ecoboost.net/forum/3...st-problems/14494-turbocharger-bov-moaning-groaning-quacking-confirmed-fix.html

Now, how many miles do you have on that '11? The timing chains on the first year or so of production are prone to wearing and causing issues. It isn't a cheap fix no matter how you slice it. Also, there is an extended warranty bulletin out there to replace the brake booster vacuum pump should that begin to act up on you.

 

[pvtschultz]

Sometimes yes, it will build boost to 13 psi but proceed to fluctuate before eventually leveling out to 10psi. But sometimes no matter how much throttle I give it, it will not build boost over 11psi. The truck has roughly 75k miles on it. Is the vacuum pump tied into the turbo boost management?

The vacuum pump only supplies the brake booster. The BOVs are operated by engine vacuum with a ~6" spherical reservoir mounted on the passenger side firewall. A check valve between the intake manifold and the reservoir keeps it topped off. The wastegates are controlled by manifold pressure (IIRC), pressure opens them. There is a wastegate check procedure from FORD that I read online that says they should be full open at a certain pressure.

I would also try cleaning the two MAP sensors first since they are a known issue. There is one mounted on top of the intake manifold, and one in front of the throttle body. Both are held down by a single screw and sealed with an o-ring. The one in the intake manifold tends to get very dirty and can affect boost pressure readings which can cause boost control issues.

The BOV solenoids can be easily accessed through the wheel well after removing the front wheels. While you are in there, take the BOV's apart (three screws) and inspect the diaphragms for tears.

 

[pvtschultz]

One more tip, install tension bands on ALL vacuum lines. Ford engineers must have assumed that vacuum lines won't leak, but they will/do as the rubber hardens. This is unfortunately coming from an engineer who is routinely asked to find ways to reduce costs...

 

[pvtschultz]

Well got the wategate P0246 code again... also my hose popped off 3 times on the way home today. If I got on it hard I could hear the sucking sound shortly after. If I got on it just enough for the turbos to kick in it wouldn't do it. I had to stop 3 times in 240km to reach in and put the vac hose back on the Turbo smart BOV... drivers side only. I'll be getting a clamp or zip tie or something to fix this tomorrow. But I've put new wastegate soleniods on and the Turbosmart BOV's in.... I'm starting to think I need new wastegates.... This truck is starting to become a bit frustrating.

There is one more place to look that I can recommend, but it's not an obvious one. There is a vacuum line in the primary intake pipe right after the air cleaner on the back/underside. I'm not exactly sure what it does, but it will affect the operation of the WG and BOV's. Put a hose clamp on that one as well while you're under the hood.

 

[pvtschultz]

I know that our trucks run much richer than stoich, especially under boost, but I don't know where they should be running. It is interesting that it is a sporadic issue with not building boost.

Can you look into the knock counts or how much timing is being added/subtracted under boost? I'm wondering if the PCM is limiting boost because of some other variable.