I posted a similar thread this past fall, but the warm-start problem continues. I just replaced the fuel filter on my '03 GMC 3500 DMax (57K miles), along with both original Delco batteries (had reached the end of their life here in Texas). The truck cranks right up in the mornings (or whenever it's had a chance to completely cool down), but takes a good 2-3 extra seconds to start when warm (that seems like an eternity when you're crankin' the starter!). The truck runs/idles fine otherwise. Start of an injector problem possibly? Ideas??? Suggesions??? As always, thanks...