Engine start, Airbag warning light, low idle rpm problem

What is your question?

06 LTD Explorer, 4.0l. Airbag warning light often comes on after start and run and stays on but not always. Associated with poor starting: too many revolutions before start and run and sometimes will not start without turning off ignition and attempting again. Usually with these symptoms the idle rpm is low, about 500rpm. No engine light.

What makes this problem better or worse?

Seems worse after long off periods but also happens when hot.

How long has your 2006 Ford Explorer had this problem?

A couple of months