burnham in4 natural gas will not ignite

Hello, Just joined this forum, looks like some very helpful people with good info. Hope you can help me with my issue. Have a 10 yr old in4 that will not ignite this season and its getting cold. thermostat calls for heat,, relay clicks, damper rotates 90 deg then stops then rotates another 90 degs. Then nothing. It is a intermittant spark type but I get no sparking to lite pilot. lwco seems to be working, drain down boiler until yellow light comes on the refill and light goes out. Flame roll out has continuity. Once the damper rolls final 90 degs I hear 3 clicks from micro switches on damper and have 24 at red wire that feeds the roll out and high limit on the stack then to gas valve. I understand that there are 3 steps that need to happen before it will attempt to lite. Any ideas?