I have a thermador PRD366JGU (6 burner, 36") that recently started acting up. The two burners on the left hand side of the range will not "hold" a flame. When turned on, the flame ignites for about 1 second, then shuts off, then reignites for another second, then shuts off. This repeats until the knob is turned back off.

In addition to this, the rear burner on the left hand side will spark randomly when the oven is not in use.

The remainder of the 4 burners function fine.

Any ideas?

Thanks a lot!