Take the cap off and check the rotor. Either the tab on it isn't contacting the coil button on the bottom side of the distributor cap, or, the tab that transfers the spark to the plug wires is bad.
With an H.E.I. style ignition, that is usually the culprit if you are experiencing a no spark issue.
'87 YJ, 4.2L built and bored, 8" of lift, 8.8 rear, AX15/NP 231J, Tom Woods drive shafts, Flat fenders, 12,000LB winch, Custom bumpers, Rattle can paint job. Never completed...