vstech is right. Do not drive the car and pull the Injector and get any loose stuff out. Inspect the Ball Pin.
Also a bad Injector with a spray pattern the sprays on the Glow Plug can easily burn a Glow Plug up.
Hunter speaking of Glow Plugs dieing due to Carbon insulation
http://www.peachparts.com/shopforum/showthread.php?t=256688