Volvo Repair: 87 760 turbo runs rich, coolant temperature sensor, mass air flow meter

Question
Dear Regis-

First thank you for your advice. This car is running very rich, rough idle, sometimes puts out black smoke and will stall. Replaced correct plugs. Had asked a question before because it would'nt start at all, did'nt do anything to it and one day after sitting for months it started right up but with above condition?! This car has always been very reliable.Thanks again.

Answer
there are many possibilities from a leaking fuel pressure regulator to a bad mass air flow meter,engine coolant temperature sensor.It will need to be looked at for a proper diagnosis.you could pull the vacuum hose off the pressure regulator and see if fuel is leaking out of it.also try disconnecting the air mass meter and see if it idles better if so it is probably bad.

Rege