Thanks - I will definitely take this advice before pulling the pan. When hot, as soon as i hit the throttle pressure is up again 60lbs or so.If it is going back to zero on a fresh engine you really need to find the problem before you run it any more. I have had a couple of pump relief valves stick open but they still usually had 15 or so lbs of pressure if not more.
I would definitely cut the filter open.
Definitely hook up a mechanical gauge.
What does it do off idle when hot, does the pressure come right up ?