well here is my problem, one day my 1989 firebird formula 350 TPI started to bogg out and it died out. ever since than it runs very bad, but smell likes its running rich. black smoke come out of the exhaust. I have changed the o2 censor, fuel filter, and the Idle Control Motor, I had the mass air flow censor changed about 2months ago too. What could be causing it to bogg out? fuel injectors be clogged? or is it time for a rebuilt? i have 109,000 miles on it but i had the heads and everything rebuilt at about 90,000 miles. I just cant figure out whats wrong.

 

replace every sensor you can think of that wears out. You're on the right track with the O2 change. If it only smokes with a black color, then its not anything mechanically wrong. You may need a tuneup on that car, but for the most part it seems light and cheap to fix.


try starting with the ignition system... spark plugs, wires, cap/rotor, even a coil for some extra juice. looking at $100 in OEM parts or $150 in upscale performance (MSD blaster coil, MSD wires, etc)

 

should i change the distribuator and rotor and plugs and wires? the wires and plugs were changed before winter. what i dont understand is sometimes it runs fine then sometimes it runs like ****

 

well if it runs fine then turns to crap, it's a sensor.

 

Might want to check the vacuum line going to the fuel pressure regulator. If you pours out you have a ruptered diaphram.

 

how about the distribuator and the rotor being bad? would that have the same effect by not firing all the cylinders?