95 ck silverado rough idle and dies

O.K. here goes no one has the answer for this when i start my pick up in the morning it takes 5 to 10 secs to start sometimes it stalls right away ....... when i restart it and give it some gas the choke picks it up but when i start driving say from a light or a stop sign from a complete stop it totally bogs down the rpms stay up but the engine bogs down and some times back fires out the top of the carb and then stalls after i start it again it does it all over again also it shifts hard but runs alright when fully warmed up i noticed if i let warm up for 20-30min it runs better but the way it should i changed the plugs wire and cap i checked my pcv valve and all is well i have no clue what to do next HELP!!!!!!!!