For the sake of safety, I must expand on Larry's previous comment:

If the high-pressure jet from an injector hits you, it will cut you. If diesel fuel gets into your bloodstream, even in a tiny amount, you will die.

"Be careful" is an understatement. Unless you have the proper tools and training for checking injector spray pattern, don't try it. Leave it to the professionals.

- Nathan
'83 240D "Steiner"
'00 New Beetle TDI