Hello, this is a 1985 Mercedes Benz W126 380 SE. I am performing a cold start to show you guys what my car is doing. The idle will drop down to about 700ish rpm then keep dropping and eventually stall the engine. About a week ago, the oil pressure would drop to zero before the idle rpm would drop, also causing the car to stall; however, this time it seems like the oil pressure is maintaining itself. I am wondering what could be the cause of the engine to stall.