I don't really know much about cars. But my b2500 has a problem with the idle. When I stop at a stop sign, most of the time it stalls out. And when it doesn't, it putters like it is about to stall. It is a manual transmission if that helps.

 

How many miles on the truck? When were the plugs and wires (all 8) replaced the last time?
Maybe you need to clean the throttle body and the idle air control valve. Also make sure all vacuum lines are intact and connected.

 

has over 200k miles on it. I checked the hoses and they were not leaking but I will check my air idle control valve tonight