GMC Sierra 2500 Forum : “hard to start”

hard to start

RE: 1999 GMC 2500. When the truck sits for longer than 10 minutes after being driven, it will be difficult to start as if it isn't
getting enough gas. I pump the gas pedal and it eventually starts, but is rough for a couple of seconds. I don't have this
problem if the truck sits for several hours or over night (it cold starts great). Any ideas?