Where is your low speed needle set? While it's idling is it creating a puddle on the ground under the pipe stinger? Try two turns out for starters. Is it a brand new truck? Are you removing the igniter as soon as the truck starts? You may be too rich on the LSN.

Mine came way rich on the low speed needle (LSN) and the high speed needle (HSN). When the truck is cold I sometimes leave the igniter on it for a minute while it warms up.