1995 Chevy truck problem?

I have a 1995 Chevy truck 350 engine with throttle body injection. I drove it a short distance last week ran fine now i started it black smoke and it wont stay idling sounds bad like not firing on all cylinder The question I have is there a choke on TBI or something that could be sticking. The truck does sit alot in the summer. Please help got to get it ready for plowing?