so my Jimmy has developed a pretty bad stumble while driving. its noticeable at idle, but not near as bad when i accelerate from a stop. i stumbles and misses badly at part throttle; feels and sounds to me like its not getting fuel, but i could be wrong. if i give it a lot of throttle, the stumble goes away briefly, but comes right back as soon as i ease back out of it. seems to do it at all temps, at all times now.

the fuel filter was changed last year, just recently changed the plugs, cap and rotor. made sure timing was set correctly, and i just took the throttlebody apart, cleaned and blew it all out, reassembled with no change at all.

anybody had these problems before? i'd really like to get it sorted out before it gets too cold out; any help would be greatly appreciated!