pilot lights, inducer motor starts, no burner flame

HELP PLEASE,
I have a 20+ yr. old Heat Controller furnace. Model # GRD100-D4. The pilot lights as it is supposed to, the inducer motor kicks on, after that it doesn't start clicking(igniter) as supposed to. The pilot stays lit, the inducer motor keeps running, until I shut it down. But nothing else happens. It worked fine until 2 days ago. You could always hear a few small clicks and the pilot would light, about the same time the inducer motor would start, then 20-30sec. later the igniter would start clicking, and the burner would ignite, and the blower would start, the inducer would shut down and all would be fine. Can someone help me? I can't afford to randomly replace parts. So I need help. THANKS ANYBODY, Matt