1990 Honda Accord runs fine when cold then runs real sluggish and hesitates very badly when gets to operating temperature please help

when was last good tune up?cap,rotor,plugs,wires,air filter,pcv valve?take the cap off,see if any oil inside it,check the rotor on the tip for being burnt.any oil in spark plug tube wells? careful on that one when taking the cap off,the ignition coil/icm is inside the cap.