i have a '97 cherokee. when i loosen the adjusting bolt on the idler pully the pull doesn't move. is there more to it than just the tension adjusting bolt?

check out this sight. http://www.autozone.com/home.htm .
I would have looked it up for you but I dont have the engine size

I looked it up no problem. If you have no power stearing, the tentioner will Idel by itself and there are no other bolts to work with.
If you have power stearing, there are two bolts behind the pully, You have to loosen them, adjust the tentioner and then tighten the two lock down bolts. I copied this from ther manual:
ADJUSTMENT
It is not necessary to adjust belt tension on the 5.2L or 5.9L engines and on the 2.5L and 4.0L engines (without power steering). These engines are equipped with an automatic tensioner. The tensioner maintains correct tension at all times.
I had to correct myself.

The 97 is not adjusted at the power steering. Only early vintage 4.0 L had that. No V-8 were used in the XJ series Cherokees.

You have to loosen the 15mm nut in front for the adjuster to move the pulley up or down.