hello, I have a 230 sl 1966 fuel injected engine. My concern is that when the vehicle is started cold, there is a lot of black smoke emitted from tail pipe(when revved) and the vehicle runs rough. As the motor runs and warms up this improves and dies down but is still quite rich (noted by eyes watering badly at tail pipe) but black smoke has died down (when revving). I have tried to understand the relationship between cold start valve and the air intake, it seems to be injecting more fuel but no noticable increase in rpm to compensate. I have a merc oem manual but this jumps all over the place and is very difficult to understand.
Please help.