Quote
Remove the distributor cap and see if the #6 terminal is damaged. Check continuity from the #6 outer terminal of the cap to the inner terminal..... check continuity of the plug wire.... check the plug..... or treat the truck to a new rotor, cap, wires and plugs.

Frank

You should find your problem if you follow Franks suggestions. If all that Frank suggested is good, look down at the optical plate in the distributor and make sure that all of the slots in the plate are open and free of debris or oil.
Conner

Over the hill but still climbing.
88 Montero 2.6L auto, manual hubs, cooling fan conversion gps,recurved distributor,LSD Diff.