New info on old problem. can anyone help now?

[3400Camaro]

i'm sure some of you have read my other post and know my problem, but here it is again. reving the motor produces black smoke and carbon to blow out the exhaust. plugs that are only a week old are carboned terrible. performance is awfull. more on that, performance seems to come and go. somedays it's great, for a 3.4. other days like a few day ago, my dads 2.2l S10 was walking away from my car. and sometimes under hard acceleraion if you floor it, nothing really exciting happens, but if you let off a bit, it will throw you back in your seat. i've had it to 2 mechanics who have both had it on the computer, everything checks out good. i've had a motor vac done to remove the carbon, no help. coil packs have been tested and are perfect. a friend of mine says maybe a throttle position sensor? could that be? any help is greatly apperciated.

[sped214]

Not familiar with your problem, but have you checked your EGR? Try putting a blockoff plate underneath it and driving that way for a while. Maybe it's stuck open and filling your intake with exhaust? Just a guess...

[v6maro]

Have you checked for anythign wrong with the trans?
-Steve

[3400Camaro]

the egr vavle has been checked, it's good. but i haven't done anything with the transmision. it's a 5 speed by the way. what really gets me is that the problem comes and goes.