Bogging down at deceleration...

I have a 91 XJ/4.0. When driving, it drives and shifts normal but when I come to a stop or begin to slow down, the RPM start to decrease alot. Even gets to the point to where it actually dies slowing down or when I stop. I'm not sure what it is but im guessing vacuum line but not sure where to start...do you guys?

Sounds like your torque convertor is staying locked instead of unlocking when you hit the brake or slow down.

Take it for a spin at about 50 ish mph and as you're driving, tap the brake pedal with your left foot, does the rpm gauge jump up about a notch?