the cost of cleaning and re-gapping the spark plugs versus replacing them with new ones is not that much of a difference in cost of parts compared to the cost of labor (time). most newer cars have either platinum or iridium plugs because of this reason plus the reduced chance of stripping your spark plug holes. the plugs now are of the time change type.


btt

try reorienting your distributor by re-clocking it and rearrange the cylinder configuration on the distributor cap to see if it is the engine or the distributor(or cap) is the cause. if by reconfiguration or re-clocking of the distributor transfers the misfire to another cylinder, then it is your ignition that it the problem. for example: since you have a toyota four cylinder, your firing order is automatic 1-3-4-2. re-clocking it could be done by re-assigning cylinder 1 of the engine to supposedly cylinder four of the distributor cap, hence, cylinder 2 and cylinder 3 of the cap will switch position. then see if cylinder 2 which was good now turns misfiring. this engine is a dinosaur and should not be too difficult to figure out. simple old mechanics. think mr. watson