I bought this 83' Firebird (V6 - 2.8L 173ci) that hasn't been started in a year, replaced spark plugs, wires, oil, and fuel/air/oil filters. It's starts right up but blows black smoke when i step on the gas in park. When i go to take it around the block i push down on the gas and it feels like it is going to die, like there is a something clogging the fuel from getting to the carb. if i gradually press the gas it will go faster but once i hit a stop sign i have to start the whole process over. Am i missing something here?

 

Fuel Lines must be clogged, Simikar thing has happened to two cars of mine, I just used some seafoam and started it and revved it for a few minutes until the idle stabilized itself because for the first 3 minutes if I let my foor off the pedal it would die and naturally they had been sitting for a couple of years, also check the fuel mixture see if its running too lean.

 

Seamfoam and Fuel injector cleaner or carburetor cleaner is what I've used for my Carbed cars & Fuel injected ones.

 

Thanks for advice. I bought the Sea foam and put it through my fuel line and sprayed the carb out with carb cleaner. It idles smoother now but no change in the acceleration or black smoke. i will let it run tomorrow for an hour or so to see if the sea foam will work its magic. thanks again

 

If after a week of running and using seafoam and carb cleaner and new Gas, I'd say its gotta be the engine has worn parts like valve seals. Might wanna replace head gasket.