This is exactly what mine was doing - identical! - I was stupid and listened to a lot of people, spent a lot of money FOR NOTHING, I did coil packs (6 good spare ones going cheap), plugs gapped with three different settings, fuel filter etc etc, at the end of the day it was the fuel pump strainer, its a little filter on the bottom of the fuel pump, forget about replacing it, Ford will try and sell you the whole pump and assembly, thieves!!! below is a link to some pics of it, it should be white and clean, once it was off wham, better than ever. Leave your plugs alone, the factory ones are fine, you can reduce the gap, but really unless your pushing big boost forget it. I also as part of the mission checked all the hose lines and clips on the turbo system to make sure they were all fitting and tight, one was loose but didnt resolve the issue. The fuel pump assembly is under the back seat, its about a 15 minute job with the only pain being the clips on the feed, return and breather hoses on the top of the assembly, the pump is inside of a big plastic, in my mind "design fault" don't be shy trying to separate it, it will come apart with even steady pressure, do not attempt to take off the fuel line to the pump, its not the type that will go back on, or take it to your mechanic to do. http://gallery.me.com/taylor.family#100140