What kind of Saitek do you have?
in controler map, you can click "Default". this should assign all analog axis to its respective function (caution though, i think you loose all button mapping). You can try to assign manually as well.
Highlight "Throttle" in your list and click MODIFY, assign the throttle function. To check if its working, open the ADVANCED field and check the lines in the blue box.
Let us know how it turns out.