Interesting comment on the pcv ... this high idle started after I replaced the gasket pcv valve and hose. I checked the seal to the crankcase , but I’ll recheck the hose and the valve itself.
if its not sealed, your engine probably cant overcome the valve(if gasket) which would increase pressure in crankcase + blowby, but if it stays open, its a vacuum leak that would affect how advance works(im assuming it would affect it much like F/A ratio) also would run leaner, which is hotter, which also could mean pre-ignition so it would behave like it needs to retard timing
