Starting Problems 4.8is

[alano]

Hoping I can get some help here.....a year of headaches and lots of $$$ at the dealer hasn't helped.

My wifes 2004 4.8is occassionally won't start. There is plenty of cranking power it just seems to 'choke' as if it is barely catching...when the cranking stops, it idles at what seems like 200rpm then dies. If she waits 1-2 hours, it fires up perfectly.

It only happens in the winter but not when it's extremly cold.
It's never happend while parked outside.
It only evers happens after it's been parked for 2-3 hours.
There is no fine line of starting or not, it either starts perfectly or not at all.

We've changed the battery, installed the 'freeze up kit', and done service II. I don't know what else to do...the dealer can't replicate it and if they blame on the battery one more time...I'm gonna snap.

Any ideas would be greatly appreciated.