...you took an injector from a 3.3 (petrol) and tried to fit it on a 2.5 (diesel)?!?! You pushed the car around, did you hear any compression, it could be piston rings loosing compression. If indeed piston banged the injector, you could have a cracked piston. Try turn it by hand from the crankshaft, if it doesn't spin the piston/s are sized, if it does spin but there is no compression is one or more piston rings. If you have compression and the engine turns by hand OK, it could be that the different injector (not by appearance but by the inside parts set on different values) kicked in the auto shutdown?! Hope it helps.