I am having a problem where the "gas jets" are not firing all the way through... meaning the first one with the glow igniter fires and the second "jet" fires immediately, but the flame does not continue to fire the third and fourth "jets" which does not put a flame on the sensor located at the fourth "jet". The gas then shuts off and it attempts to light the furnace again. It makes about 4 attempts and then locks out. I can get it to fire all the way through all 4 "jets" by adjusting the "jets" by unscrewing the bracket and aligning them. The furnace will then fire up and blow heat. This will last for a day or more, or it will not fire again properly on the next cycle. I noticed that the third "jet" is able to be wiggled pretty easily, where as the first, second and fourth "jets" are pretty tight. I am wondering if through vibration the third "jet" is moving out of position... ever so slightly... causing the flame to not be able to travel all the way to the end. Any thoughts?