[kuehl]

The sensing bulb (copper pigtail attached to top of evaporator outlet pipe) throttles the TEV; opening and closing. As the evaporator outlet temperature rises the TEV opens, as the temperature drops the TEV closes; however TEV's never fully close. You could test the flow rate (air moving through the TEV) by submersing the sensing bulb in ice cold water and then warming with your hand.

For safe measure, I would inspect the entire high side circuit just to insure you have no visible restrictions (crush hoses, bent or crushed ac fittings or condenser coil tubes).