PCV Diagram?

[ShepT]

My 85.5 944 sometimes likes to idle super high at random, typically when warmer. Around 2000 rpm and is also very sluggish to rev down between shifts/off throttle. I originally assumed it was a vacuum leak so I smoke tested it today. No leaks. What I did notice though was that smoke came out the oil fill. I was curious to see how this related to the pcv, and also reading around old forum posts it also means it could be drawing air through the vacuum system if the valve is stuck open?? The oil separator is fine and everything related to that is clean and not cross contaminated. The car will idle down and run better if I floor it for some reason, making me believe the barn door for the bosch intake controller thing gets stuck at certain points. This is stumping me and I thought it would be best to ask here.

[v2rocket_aka944]

There is not an actual "PCV valve" on a 944 engine.

The Air-Oil separator, the black plastic can thing that you fill the oil into, pulls in oil vapor at the top from the crankcase, spins it around and drains the heavier liquid droplets back into the oil pan.

Lighter oil vapor gets pushed out of the top of the AOS, into a hose that connects to the throttle body boot ahead of the throttle body. The crankcase is not put under any vacuum, the system just vents pressure in the crankcase that is above atmospheric pressure.

Doing the smoke test into the intake tract or into the manifold can make smoke come out of the oil fill because it is all connected together. There is a small hose that connects to the bottom front of the intake manifold directly from the bottom of the throttle-body boot (sometimes called the J-boot on 944 forums).