I have '87 BMW 316 (not EFI - carburetor). Car was not in use for few years, and now engine runs rough on a cold start, and black smoke comes out of exhaust (too rich?).
When I try to accelerate I feel like I have a trailer behind me - jerking, and poor acceleration. When the engine warms up it is somewhat better, but it is still there.
I sent my carb to carb repair shop for ultrasonic cleaning and overhaul, but no luck. I adjusted valve clearance, spark plugs are new NGK, new cap and rotor arm.