Sounds like a 1/4 inch hole drilled in the bottom of your fuel tank! Someone is not out to get you??!! Does it run rough and have a distinct amount of black smoke out the exhaust when you start it or step on the throttle? Sounds like a O2 sensor or something is sending max fuel somewhere it shouldn't. I think Bee Utey is on the trail about your timing and how the engine runs. Tell more about if it is rough at idle or low on power. Does it take a long time to warm up (operating temp)? When was the last new air cleaner given to it? There is not a miner bird nest in the intake piping?? Or a carpet snake? It might help if nothing obvious comes up to get those injectors checked. Maybe have a look at the new bosch gen 3 injectors which go well in the 4.6. They actually atomise the fuel instead of squirt the piston like a water pistol (gems injectors) :(.
This guy does a bunch of videos on the bosch type 3 injector compared to the lucas types. Have a look. [ame="http://www.youtube.com/watch?v=7oTirEZNRw8"]comparison of Lucas type disc injector to Bosch design III to the stock GM multec. - YouTube[/ame]
Cheers,
Brian

