My new 2006 Ram 2500 seems to be taking an excessive amount of time to fire up on cranking. Cold starts (air temp > 59) in the morning are taking as long as 4-5 seconds, which seems a long time based on years of listening to diesels start after overnight in motel parking lots. Starts during the day,both cold and warm, are usually shorter (1-2 seconds). Are 4-5 second cranking times normal behavior on the 5. 9 Cummins?