See if they can test the alternator too.
Now the fun starts. All four of your symptoms (boost cut, idle stalls, hunting idle, and overall performance) could be coming from an intermittent open circuit between the battery/alternator and VPWR V monitoring point, or an intermittent short to ground somewhere in the car. It could also be something else, like a faulty regulator on the alternator (odds are the standard alternator test would not catch an intermittent of a few milliseconds' duration), a failing coil driver (built into the coil), or simply a loose connection, to name a few. What is VPWR V, exactly? Is it power to the ECU? Knowing this can help narrow the search.take it apart and check all the wiring harnesses
These measurements are probably not telling you the whole story. Here's why.By far the worst voltage I got was when I shifted into neutral and revs dropped. When they dropped i saw voltage drop to 13.0 - 13.1volts.
If voltage dropped below 13 to 12.9 or 12.8 thats when the car would stall on me and it would stay around 12.7 until the bump start took it back to 14.1
ECU is commanding the turbo bypass valve open when it cuts boost. That's usually the third and last thing it tries before dumping the throttle when it senses knock, but it might do that for any fault condition it deems severe enough.How sure are you that E55Boost is actual boost and not the requested boost? I'm not familiar with that logging software but I find it hard to believe the sensor works in every range except for around 15 PSI. I'm curious if the ECM is sensing knock or a condition that merits dropping boost, and the E55Boost is the request not actual. If the car feels slower on both tunes you may want to make sure your cat isn't clogged or your purge valve isn't intermittently stuck open. A clogged cat isn't common, but could cause this issue. Really weird; can't wait to hear the outcome!
Do you have a modified SID, or other monitor display? Or is voltage monitor peculiar to V6 or XWD? Stock SID won't show system voltage according to WIS, my owner's manual, and checking on my car. Where is the data shown in EFILive in your first pic coming from? Can you confirm it is all coming from ECU?Ummm I have no idea. I was just watching it off my SID. Although I have some mechanical skills. My electrical skills and knowledge leave a lot to be desired
Best reason I have ever heard for getting a copy of the WIS, by miles!my parents taught me to always use protection
It tells you there's a fault in the harness (or something nearby that's connected to it). You can easily repair a frayed wire shorting to ground, and they are easier to see than internal breaks. You can also replace or splice around an internally broken wire as long as you can determine where the break is*. These are easier/cheaper alternatives to replacing harness.What does it tell me if the car does stall or have hinting idle after I push the connector to the ground?