Do some research on the Injector Pressure Regulator (IPR), I have a strange feeling that could very well be your problem. Which oil pressure is building to 150? the low oil pressure, or the high oil pressure from your HPOP? Are you sure its an Oil issue? could easily be a fuel issue, or an electronics issue as well.
Originally Posted by heavy mechanic
I have never been stumped till this.
Something is telling me this isn't the first, and most definitely will not be the last time you will be stumped!