I replaced my PRV less than 10k miles ago with a new Mazda factory part. Just ran out and ran the test again. it went to 1835 before it popped off but it took F O R E V E R to get there. Like 20 mins. When I ran the test last time, I thought I remembered it taking less than 5 mins.
I understand why we run this test and why it is valid, but I do not understand how it works. I don't understand how pressure climbs without the cam turning and pumping the HPFP. Is it purely the fuel heating up in the rail?