I had a similar issues with an the 2.6 in my '88. I tried everything. New plugs, wires, coil and timing. Adjusted the carb and it still misfired. What it turned out to be was a broken cam cap on the top of the head. It wasn't allowing the valves proper operation as it cammed over. Simple fix was to replace the cap. I lucked out that there was no real damage to the camshaft. Your problem may not be related, but it's worth a check.

1988 SWB Montero - 2.6L - 5-speed
Weber Carb
(Coming Soon) Rugged Ridge AVM Hubs