1994 Cadillac STS rough idle and stall

THERE IS A FEW THINGS I COULD SAY ABOUT THIS. FIRST HAVE CHECK DONE ON THE COILS AND ELECTRICAL SYSTEM. ALSO O2 SENSOR PLAY A VITAL ROLE IN THE RUNNING OF YOUR AUTO. THAT IS WHY YOU HAVE 4. CHECK THE CODES ON YOUR ON BOARD SYSTEM, EVEN THOUGH YOU MAY HAVE CHECKED THEM ON OBD CODE READER. THE LAST THING I WOULD SAY IS TO CHECK YOUR FUEL SENDING UNIT. A SHORT IN THE FUEL PUMP WILL SOME TIMES RESULT IN INTERMITANT SPURTS OF COMBUSTION. CHECK FOR CODES IN YOU HISTORY OF P0140'S P0150'S- O2 SENSORS, P0300'S MISFIRES ( IF IT IS A CERTAIN CYLINDER IT WILL READ IT, IE. P0302 MEANING CYLINDER 2.) AND LAST BUT NOT LEAST FUEL INJECTOR CLOGGED. AND FOULING OUT. CHECK CARBON ON THE PLUGS. MAN THATS ALOT BUT I'M STEERING AWAY FROM HEAD GASKET ISSUES.

I had a similar problem with my 93 sts. It had a hard time idling in the mornings when the engine was cold (< 50 degrees F). I heard the idle speed control motor making a repeating clicking sound - usually 6 clicks- every time I started the car or turned it off. The problem stopped when I replaced the ISC motor. (Now I am trying to get the idle speed down!)