Misfire cyl's 1,3,6

Have you tried replacing the ignition coils? If they get old and stop working, or if they're damaged, they won't send a strong enough spark to the plugs. AutoZone (I think) apparently does free diagnostic codes for a check engine light. I don't know if you have a check engine light on or not, but maybe the light burned out? It might be worth a try to call them and ask if they can check the codes for you for free.