Whirlpool gas range, model SF362LXTB2 when oven is set to bake the surface igniters (All 4) spark but no spark to the bake igniter. I initially thought it was a grounding problem so I devised a separate ground wire from the igniter mount screw to another screw about 16 inches away to ensure a proper ground. No luck. I then pulled unit out, removed rear panels and checked wires, wire routing, and spark module for burnt parts. I then tried both bake and broil modes and they worked O.K. Reassembled, slid in place and back to orig prob. Then I pulled it out again, pulled off rear panels checked wire connections to spark module (all OK) and when I tried it everything worked correctly. Reassembled, pushed back and guess what, orig prob is back. I checked the outlet to ensure proper polarity. I suspect spark module problem but I'm suspicious of a wiring problem. How else can the spark go to all 4 surface burners rather than the bake igniter?