had this one last night. inlet pressure is 6.9 and outlet pressure is 3.45. i cleaned the burners but the only one dirty was the first one that is rolling back at start up. cleaned orifices. still has roll back at start up. i did notice when i was turning the furnace on and off to check it, that if i didnt let the inducer completely stop before turning it back on it wouldnt have roll out. what do yall think?