just crank it a second longer and it won't feel like that..

most 4.6's I know of do this, its actually fun to see how many start by themselves with just a flick of the key
however when I first got my 02 it did this bad.. it felt like it caught so I'd let go of the key, there'd be a moment it does nothing, then it'd fire up...
I replaced the air filter and fuel filter and it hasn't acted up again..