I would be more suspicious of the small return lines on the injector. They harden with age and no longer seal as they should. Pretty cheap fix with one meter of line capable of many replacements. Don't forget the small plug in the end of the last one.

Normally, if it is an injector or line, the diesel fuel would be "everywhere" due to the high pressure. If you have ever forgotten to tighten one down, after working in the area, you will know what I mean.

__________________
Sam

84 300SD 350K+ miles ( Blue Belle )