'89 XJ bucking in reverse

I have an '89 XJ Limited with the 4.0 and auto. It runs great except when I put it in reverse it bucks and jumps when I accelerate and acts like it is going to die (it never has). When it is in 4-lo, the problem is worse. It only does this in reverse. Any ideas on where to start with this???

Thanks,
Kelly

Mine acted just like this, it was due to loose bolts mounting the bellhousing to the motor! The torque would throw off the CPS, It only really happened in reverse. I also had bad motor and trans mounts. Check and make sure everything is tight.
I thought it might have been the torque converter, I had a little suprise when I went to install one. I ended up just putting some locktite on the bolts and re-torqued.