Hi everyone. I'am new to this site , hope someone can help me. I have a 1991 Trans Am convertible 305 TPI. Blows black smoke out exhuast when starting, will hesitate at about 80 km/hr. engine light comes on, can smell unburnt fuel . seems to be getting more fuel than it burns. new plugs wires, distibuter, check EGR seems to work, no vacume leaks. Could it be oxegen sensor or something else.
Any help would be appreciated Thanks.

 

Identify what codes it is throwing first and then you can decide what the likely failure modes are. o2 sensor is a good idea but there are many posibilities.