engine skips aroung 1800 rpm

i have 87 xj 4.0 with auto when i get up ot 1800 rpm the motor seems to start skiping or misfire any ideas other wise runs fine

Skipping around 1800-2000rpm could be due to an incorrectly indexed distributor, a worn distributor shaft, or worn distributor drive gear.
Remove the distributor cap and see if there's any wobble in the shaft. Badly grooved terminals in the cap will be a clue to that. Also rotate the rotor by hand to see how much free play there is in the drive gear. If it moves several degrees, the gear is worn and you need to remove the distributor to replace it.