Pacific Fuel Injection in SSF is highly recommended.
Gus is the man there.
He checked a set I had laying around for $25 (several years ago). I had the pleaseure of watching while he did the work, its an interesting process.
To clean and calibrate a set is about $30 per injector however maybe more for some types.
Just checking them for spray pattern is simple and only takes a few minutes.
If however you catch him busy, he will probably tell you to leave them off, that little shop get busy at times.

Dieseldiehard
1971 220 (gas) 4-spd manual 102600
1979 300TD w/ ’85 turbo engine 288,090
1983 300D 234,200
1985 300TD 202,820