4kq stumbling

[GMBCHEF at aol.com]

Hi gang. Glad to see the list is up again. I missed all those emails!
My 86 4kq is acting as though its over-carbureted and won't accelerate very 
well over 4000 rpm or at any throttle position past 1/2 way. Also, it's 
idling rough. This all started very suddenly when we got our 9" snowfall here 
in New Haven. 
Sometimes it will backfire through the intake at startup when giving it gas.
Any solutions?
Gary Brown