88' TBI 454 running a little rich

[Chevy3+3]

This has been a problem since I bout the truck. I'm starting to wonder if its just the nature of the beast. The truck runs alright but whether its cold or warm out it always seems to puff black smoke from the tail pipes when starting out from idle. If you feather and do small pumps on the throttle pedal the truck will load up some like its choked.

The timing is set to 5-6 degress BTDC (with bypass wire unhooked). I have new plugs, cap & rotor and plug wires also. The TBI injectors are pulsating and not dripping any so I think I'm good there. I have also made sure all vacuum lines are good and have no leaks. I replaced the TBI base plate gaskets also. I also replaced the coolant temp sensor that controls the TBI. I have the same results with the new sensor as I did with the old sensor.

I haven't replaced the O2 yet. Could that be my problem? My check engine light is not on so I assume the O2 sensor is okay?