I browned a pork roast and put it in my crock pot. 1 1/2 hours later I discovered the crock pot was unplugged. Is it safe to eat?

This question is one of those that gets a wide range of answers, depending upon how 'by the book' or risk-averse you are. My answer is 'i wouldn't hesitate to cook and eat that pork." But then, I am not a 'by the book' person in anything, and I firmly believe that there is MUCH more flexibility (w/o being dangerous) with proteins at room temp. If you had said it sat overnight at room temp, i would probably counsel you to trash it, but 90 minutes? doesn't concern me in the least. Heck, I'm sure there have been a dozen times that i have seared meat for boeuf bourgignon or other, and i've been distracted or called away, and returned to the cooking a few hours later, and 40 years later, we're all still alive and kickin'! just sayin'.

By browning it, you moved it well into the temperature danger zone. The fact that you're asking the question says that you likely know its answer: No.