Well....I gave it one more shot before I ordered a new HPFP. First, I checked all the plugs after the car sat all day...all dry and look fine (no leaky injectors). Then I hooked up MHD, got a log running, and fired up the car.
This time the HPFP never got above 50psi...the motor sputtered and coughed as it attempted to idle. After doing that for around 10 seconds, the HPFP came to life and the pressure sprung up to around 2,600psi and the motor started to idle normal.
At this point....I'm 110% sure it's a HPFP problem. I think something is jacked up with the built in fuel pressure regulator. I'm going to order a new one off of FCP Euro tonight, along with a new rail pressure sensor.
I will report back after the parts show up and I get to take the car for a test drive.
datazap.me