87 300TD 15 ATDC confirmed... still smoking

[locry]

I have an 87 300TD... had injectors balanced at the recommended pressure... I don't remember exactly what the pressure is but its the norm I'm sure.
I have black smoke issues during acceleration and puffing smoke at idle even when warm. I checked the timing earlier and it's 15 atdc. (aligned crank marks at 15 atdc and peeked through the IP hole)

what could be causing the black smoke... it IS unburned fuel correct? I tinkered with the "flapper" valve directly below the air filter.. since its been disconnected for ages I figured I'd just jam the flapper door open for good measure. Will see if the smoke improves.

Opinions are welcome...