OK I just wnt through all of this with my car
At frist startup oil pressure was normal then as soon as it got some temperature it would go to nearly zero
I did the check with a mehanical guage and it agreed with the stock unit
Then I thought about my oil (Turbolight 10W40)
I changed it to penrite 10W60 and the problem was solved, Simply put the lighter oil could not take the heat and broke down as soon as the car got up to temp!