What engines in the car?
I know with the more recent 1.9TD VW engines you are ment to use a special injection socket to remove the injector.on the 1.9TD engine their is a black shape washer that sits between the injector and the cylinder head this acts as the seal. the injector on this engine is very tight, i cant remember the tightening torque off the top of my head.
hope this info is some help
