My sime super 90 has developed a delay in igniting?

Hi can any1 help me
I have a Sime Super 90 that ive had 4 sometime,but now its developed a delay in lighting,sometimes the igniter will click 4 some lenth of time before the relay open's and it fire's up, and other times the fan will start and run 4 a lenth of time before the igniter starts clicking,but once its fired up it's fine when you shut it down and re light it. please, please can help anyone help :-D