if you can tell us what kinds of sounds it makes, if it tries to crank over, does it even make noise (I'm assuming it does if what you said above is true), there is also fuel in the pistons that isn't burning due to the leftover fuel on the plugs. If you can give out sounds from different parts (especially abnormal sounds) that would help a lot. SOunds as if when you stick the plugs into the engine block you ground them out maybe? because it sounds as if their not firing when you put them in... then again maybe your always checking them after fuel injection/before firing...