Problem with Janitrol furnace not lighting correctly - Model # GUI075-3

[NickG]

I have a Janitrol furnace model #GUI075-3 manufactured 6/87.

The control board is a B13707-24.

Here is a description of my issues.

When I first turned on the furnace for the season the pilot would light and the igniter would continue to spark but would not light the burners. The controller would finally time out and shut down and re-attempt 2 more times. I sometimes was able to get the burners to light after cycling power or blowing some air into the pilot area.

If it did light, the burner would continually go out and the igniter would come back on and re-attempt to light and sometimes would and sometimes would not.

I decided to remove the ignition assembly that held the flame sensor, pilot and igniter.

This ignition assembly looks like the one on this page:

http://www.arnoldservice.com/goodman_janitrol_parts1.htm

Scroll down to where it says Goodman Janitrol Spark Pilot Ignition Assembly Part #B1401003S

Upon doing so I found the tip of pilot had crud on it so I cleaned it off and made sure the tiny pin size hole at the end was unobstructed. Once I replaced it and turned it back on the pilot flame was twice as long as before but it still had trouble igniting. Typically after trying for a while and me cycling power or blowing a little into the pilot flame it would light the burners and this time run it full cycle and not go out.

So in summary, cleaning the pilot light opening was able to get me to the point where once the burners were lit the furnace would run its entire cycle and shut off normally. The problem now is just the starting. Also I replaced the flame sensor with brand new one and no change in the symptoms.

I have included a link to a Youtube video I have made that shows what I am dealing with as well as some pictures. I hope they will further help show the issue.

I guess now I need to know how to troubleshoot the signals coming out of the controller to make sure all the right voltages are going where they should. I am at a loss on why the flame sensor does not seem to work right when first lighting the burners but seems fine once the burners are lit.

Thanks in advance for any help you can give me.

youtube video link:

http://www.youtube.com/watch?v=GfiOVNhMIQU

photo link:

http://www.flickr.com/photos/18573373@N04/

[RegUS_PatOff]

YouTube video not set to "public"

[NickG]

Well that was dumb. Ok video is now set to public viewing.