2006 Ford Mustang Rough acceleration from stop.

Take the injectors and the spark plugs off have one person shine a light into one injector hole see if you can see the blue plastic piece if you cant see it turn the engine over untill the piston comes to top dead center try to remove the plastic piece with skinney needle nose pliers through the spark plug hole make sure NOTHING else gets in there use water and air compressor to remove the dirt before trying to do this move to the next piston repeat the steps

if you cant get them this why continue to dissasembla the engine down to the head, remove the plastic, check the valves and pistons for damage have the head shaved and pressure tested then replaced with new gaskets and spark plugs
you will need a repair manual to know the proper torque and tightening sequence to put the head back on and a click torque wrench

Well, I took off the injectors and looked in there and couldnt see anything. After I put it all back together the engine worked better than before.