Morning sickness
 

I have an 89 Na auto. Sometimes on a cold morning ill start it and take off. Half way down the road the thing will start missfiring really bad. sometimes it wont start at all after this so I will leave it alone after awhile it fires back up like nothin ever was wrong. when it is running really rough it dumps fuel (black smoke) just wondering if you guys might know whaats up

Timing.
Sometimes the distributer cap can crack and let moisture in causing misfire.This problem is worse in a humid climate such as the one I live in.
Throttle body problems,such as a "pin hole" can cause this problem as well as vacuum problems, although rare.
May just need tune up???