560SL engine loping (suddenly runs rich)

[THEDADLORD]

My '87 560SL with 78,000 miles suddenly began running with a very rich fuel mixture. When it's first started, it idles at 1700 RPM OK, then after the idle drops down, it runs awful and has no power at all. You can smell the raw fuel from the exhaust. The fuel distributor has been replaced. Also the ignition control module and coil are recent. Disconnecting the O2 sensor has no affect.

Can anyone please suggest what device(s) might be cauing this?

Thank You in advance for any kind of assistance.

William