Off-idle hesitation problem

My '89 XJ has an annoying issue with hesitation/stalling just off idle. When I try to accelerate slowly(picture sitting in traffic), it stumbles, the RPMs drop, and it occasionally stalls. If I give it more than just light pressure on the gas, it's fine. Any ideas?

Could be a number of things,
First, check the EGR valve and solinoid, make sure you have vacuum to the EGR valve on the manifold and that the little rod on the valve goes up and down.
Second, you could just have a dirty TB, Run some Seafoam down it.
Third, you might have a throttle position sensor going out.

Heres a write up on Checking the sensors. Good Luck
http://www.lunghd.com/Tech_Articles/Engine/Basic_Sensors_Diagnostics.htm