All of a sudden I'm getting this damn chattering miss at mid-range power. Idles just fine (no change there). I'm a scratching my head hear gang. Please let me know if you know whats causing this.

 

When I accelerate it bogs. seems like it might be a fuel delivery problem, but its also like the timing isnt keeping up ????

 

Adjust the secondary air valve spring tension on your Q-jet carb.
It is probabily too loose causing the secondary air valve too open too soon.

Do an internet search on "Qjet" or "Q-jet" or "quadrajet" and "bog"
to find out how to setup the carb. There is lots of info there
if you look.

 

is that something that would have changed overnight though ?

 

It's about as unlikely as the ignition timing changing overnight.
But is a common cause.
There is a vacuum diaphram that is on the passenger side
of the carb. It can go bad "over night". It, along with the spring tension I mentioned, regulates the secondary air valve opening timing. I can become bad from age or a back fire.
You can check its proper operation by removing the little rubber
hose from it and compressing the linkage while holding your finger over the hole in the nipple. The linkage should stay
compressed until you release your finger from the hole allowing the air to return in. If it won't hold, the diaphram is ruptured
They are about $30 for a new one.
The choke will not operate properly if it is faulty also.
Other thing on your Qjet equipped car that can cause a bog are.
faulty accelerator pump diaphram,
Clogged fuel filter (fuel inlet)
bad fuel pump. (in tank or on the motor)
Bad ignition (plugs, wires, cap , rotor, pickup coil, coil)

 

Thank you very much Fbird.. I truley appreciate your opinion in this matter. I will keep you in the loop and let you know which of these things actually make the difference.

 

okay check on everything but the fuel pump... how can i be sure that the fuel pump is failing???

 

If it was the fuel pump, then if you took off from a stop, it would be fine for a little while (few seconds) then fall flat on its face. Doesn't sound like fuel pump to me.

I think a piece of something, maybe even a drop of water, is lodged in a jet or elsewhere in the main metering passages.

 

Thanks RB83L69. how difficult would it be to clean er out?
Im new to the board and really appreciate your time guys

 

Put in a litre of that STP dry gas and it seems to be a little better (although it is stall bogging). I might just upgrade that fuel pump anyway.

 

turns out one of my spark plugs burnt out. go figure