Gas and Oil Home Heating Furnaces - Cleaning Flame Sensor on Heil gas furnace

Hi All, My Heil unit is Model #NUGE100BG01 1992 vintage

Before I go barking up the wrong tree, here's the overview of the current situation.

The pilot goes on after about 15 seconds of clicking, then stays on for 45 seconds without ignition of the gas burners and then the pilot shuts off. When I blow lightly in the direction along the length of the gas burners the flame takes hold and the furnace operates continuous till the set temp on the thermostat is reached.
I think I need to clean the flame sensor, which I watched being cleaned two years ago, but I am fuzzy about exactly where it is located. (My best recollection is to remove two screws mounting bracket with wires and a soft metal tube close to the pilot light along the gas rods. The soft metal tube works it's way to the pilot/starter box). Please advise me of the right course of action and direct me to any diagrams so I can be sure of accessing the right part I need to clean or otherwise replace.

Thanks in advance for your abilities and advice. Larry

What do you maybe have in the way of (a)thin electrical wire(s) that run into the combusiton area, besides the piping for the gas?

The flame sensor is not your problem. I don't recall if Heil uses small tubes between the burners or a slot. Your problem is you are not getting main burner gas near enough the pilot for ignition to take place. Your blowing gently moves the gas enough to light.
If the crosslighters have a slot in them, use a thin piece of metal to make sure the slot is open. If there are small holes, use a piece of wire.