Hesitant V8 in the morning!

My 3.5 Efi has been hesitant at the first junction I come to in the morning recently. She starts fine and runs fine up to the junction (about 100yds, bumpy lane though so slowly), then I put the power on to get out onto the main road and she stutters. Stank of fuel this morning when it happened so I assume it's ignition? Thing is by the time I get to the next junction (about another 500 yds) all is fine, and runs sweet for the rest of the day. That's on LPG if that's any help, though looking at other threads LPG tends to highlight a problem rather than cause it? I'll try the same routine on petrol tomorrow and see if it happens on that.

Need to sort it cos i'm ending up marooned on the main road outside a concealed entrance! Perhaps the old girl is like me and just doesn't like going to work in the morning.