Reddy heater won't stay on. I have a kerosine type reddy heater 55,000 btu. i plug it in and it

Question

I have a kerosine type reddy heater 55,000 btu. i plug it in and it starts and has heat but only runs for about fifteen seconds. it will keep repeating this as many times as I plug it in. i had real old kerosine in it the first couple of times i started it i'v emptied it and put fresh kerosine in it. i'v tried starting it about a undred times and it just never stays on.