I have a Maytag Neptune MDG3000AWW gas dryer that will lite in all three modes (intellidry [regular], time dry/air fluff, and intellidry [easycare/permannet press]) but will only stay lite of 8 to 10 seconds. After ltwo or three minutes it lites again for another 8 to 10 seconds. Takes all day to dry a load.

Sounds like the safety device on the burner is bad or has lost its setting. You will probably need to call for on site service unless you can test the unit and effect the repair.