[WDShaffer]

Agree with all that advice - sitting still isn't good for us or our trucks. Engine either fuel starved, or you have a leaky intake gasket leaning up the mix. Easy way to eliminate a leaky gasket is with a can of starter fluid. Get the engine idling smooth and slow. Spray the starter fluid in short bursts at each side of the base of carb, and wait between shots. Follow this procedure around each port. If idle doesn't change, no leak and proceed with fuel delivery troubleshooting.

I've had to deal with plugged accelorator jets too; like Vernski said, fuel starvation for 1 reason or another.