Yeah the vac/electric solenoid that is mounted onto the carb bowl and interacts with a screw on your throttle lever....Check it. Make sure the vac actuated portion is set right... there's a good description of setting the idle for both the vac & electric parts of it somewhere on ORC.

Also, I had much the same problem, and it turned out to be the decelerator valve (is that what it's called? you only have this if you have a manual trans.) It had failed and my YJ would die at every sudden stop.

-pablo