1998 Jeep Wrangler no power

Do you have instant throttle response in park? Check the throttle body for excess varnish and clean as necessary. Check the MAP, O2 and MAF for proper output. Also do a compression test on all cylinders. Normally a cylinder should operate at 120-140psi however this can even vary to 100-160psi. No cylinder should be less than 20% of any of the other cylinders.

Timing chain is most likely the cause of power loss however the above list might also be robbing you of your performance.