Chevy & GMC Vans

Well I decided to give the ol`astro some lovin`and gear it back up for the road. after changing a spring, and givin`it an oil change...oh, and new plugs it started. ran well, but i noticed the volt guage was very low. so while it was idling, i found that the plug for the alt was unplugged. once i plugged it in, it started to what i assume was run very rich. it also blew black smoke and started idling very rough. i haven`t checked any codes yet, but i did put my meter on the batt while it was running. i had 12.10-which i thought was low. either way i drove it to the front of the house and left it. i`m not sure how plugging in the alt would make it act all funny, maybe it was just by freak chance. any thoughts??

thanks!!

mabey somehow you upset the O2 sensor wire?

definately needs more charging voltage, make sure the ground wire is secure too, if its bad connection there it could be trying to get ground from the next closest thing and mabey thats the fuel injection sys

at least it runs!