Idle has 2 speeds. Like someone is turning a switch on and off. When the engine starts it appears that it will idle normally, but after approx 5 seconds the idle starts getting irregular, increasingly so for about another 5-10 seconds. Then it continues, Up down, up down, in a steady and predictable pattern. This continues until the engine is turned off, or the car is driven away.
No matter the engine temp. Engine is obviously running rich(you can smell it).

Under the hood I found the pcv vac hose disconnected, and the vacuum port on intake clogged. All other hoses appeared intact. Car runs strong at higher speeds.

I disconnected the Mass air meter and there was no response. Idle didnt improve, nor worsen.

Owner says the throttle body was recently cleaned.
Anyone have ideas about this one?

LS.