Top burners and broiler work but not the bottom oven.
Test for 3.2-3.6 amps at the gas safety valve with the igniter turned on. If the voltage is there, you have a bad safety valve. If the voltage is low, you have a weak igniter and the igniter will need to be replaced. You can test this with a multi-meter TJMA-DMT3. Here is a link on how to use a multi-meter. http://forum.appliancepartspros.com/oven-repair-including-ranges-cooktops/4810-how-check-continuity-ohmmeter.html
The bake burner has like an air adjuster on it and it is completely open. Can this be adjusted ?
Answer Betsy, Yes the air shutter on both the bake and broil burners are adjustable. They are usually held in place by a small screw, that has to be loosened, then re tightened after the proper fuel air mixture is reached. Basically, on Nat Gas the shutter needs to be 1/2 to 3/4 open and on LP Gas the shutter needs to be full open, after the burner has been ignited and burned for a minute or so, you'll need to "fine tune" the shutter until there is a double blue flame from each burner opening and little to no yellow or white tips on the flames.