Start-up problems have returned... If the truck sits for 6 hours or more it just spits and sputters on the first startup and dies, if I cycle the key it will fire right up??? Also, when I am just easing into the throttle off the line it feels like it is starving for fuel and my wideband reads lean. No problems at any other point, plenty rich at WOT...
I had the truck retuned to fix this last year and now it is back with the same tune being used?
I have cleaned the throttle body, maf, and replaced the fuel filter. What am I missing?

It is an 05 5.4 with a Magnacharger 83000 miles,

 

could it be caused by winter blend fuel?

 

I don't think so, I drove it all last winter after a re-tune and had no problems. I can't figure out what has changed??