Normal ICP while cranking

[rtm038]

Gotta 2006 and its been experiencing a slight stumble when starting but runs fine. It takes the engine about 2 seconds to fire up (warm or cold), during which the ICP goes from 0 to about 550 during first second of cranking. Then the engine starts and the ICP settles in at about 585 with the IPR at about 22% to 25%. When revving the engine, all sounds good and the engine runs smooth. The fuel filters haven't been changed in about 15k miles. Could this be the cause of the brief "stumble start"?

Thanks
Ryan