I have a 1987 Firebird with a 305 4bbl engine and automatic trans that I drove thirty hours down to Texas. The original engine died and out of desperation the previous owner dropped a used '86 305 into it.

It made the trip fairly fine, but a couple weeks after I got it home it started to smell like burning oil, smoke came out of the exaust and it barely ran at all. It misfired constantly, stalled, dieseled, couldn't accelerate, etc. Took it to a shop and after a couple carb rebuilds, and other such work they came to the conclusion that two of the piston rings were blown.

So, went out and got a rebuilt engine, but with my limited funds I was only able to get another '86 305 for it. None of the shops would do the core exchange if I had gotten the '87 for it.

That solved the burning oil problem and the constant smoke, but now I have a new problem.. or one that was entirely seperate to being with. The car misfires consistently, burns gas to the point that I get 6 mpg, and stalls if I accelerate too hard.

I've checked the timing, the spark plugs, the spark plug wires.. the only thing I haven't checked is the computer or the sensors, because well.. I have no real clue how to do that.

I ended up having to go out and buy a cheap car to "temporarily" replace the Firebird. It ended up being a Chevy Metro.. so, yeah, super soul crushing to pull up behind my shiney-yet-broken Firebird in the driveway. I've recieved multiple offers for the Bird and I'd rather not sell it, but after the near two-thousand dollars I've thrown at it it's becoming an option.

I'm generally just entirely stumped.. the only thing I can think of now is that it's the computer, or it has to do with the engine being the incorrect year. Anyone have an idea? Any help at all would be greatly appreciated. Get me out of the Metro. =(

(Also, it won't start right away at all. It usually takes quite a few cranks to bring it to life.)

 

Is your check engine light on. See if it is throwing any codes and start from there.