Clean fuel,full tank,new filter, bled air,new nozzle.Furnace burns fine for one cycle(3 minutes.)then pops reset when starting next time.. I have to wait 2 hours before I can run it again... if I try within 10-15 minutes reset stays down but I don't see spark or flame in view window? Ignitor problem? Help?

Check 3 things. One is the cad cell located under the transformer, second check the transformer, also check to make sure there's no black goo coming out the transformer as that's not good, then finally check your porcelains. Your problem should lie right there...