My '01 S60 (51K miles) has a curious hard start problem. If the engine is cold (as in overnight cold) or left for less than about 5 min, it'll fire right up. If left for more than about 5 min up to all day, it takes 5 to 10 sec of cranking to get it to fire - sometimes longer but I'll shut it down and retry if goes too long. Once started, it runs fine and it's not throwing any codes. The car is maintained by the book so the plugs (my first thought) are fairly new. Any pointers about where to start would be appreciated.