black smoke on start up

[monkeyhead]

I've got about 400 mi on my rebuilt short block now and got a little brave(or stupid) and showed it some boost today for the first time on my way home from work, saw 9 psi in third gear. It felt great, pulled strong. I had to run back out after I got home and a diesel like black smoke puffed out the exhaust right as I started it and then went away. I'm not sure what it could be. unburned fuel is my only guess but I don't know why there would be any unburnt. Any ideas on what or why this happened greatly appreciated.

[monkeyhead]

Is this in the wrong section? or does really noone have any Idea?

[Mario]

If it truly is black, you are correct, there is a rich condition. Care to share more of your set-up?

[monkeyhead]

it's all stock from the airbox to the catalytic converter. It only happens right on start up. Wonder if an injector is leaking or something. They have been sitting in an open uncovered box in my shed for over two years. Might have gotten dirt in them.