The Diesel Purge may have helped based on what kind of fuel has been used since the injectors were new. Then again, Diesel Purge probably has a high cetane rating and will help just about any diesel sound like it is running better. Since it won't cost anything, you might consider taking the injectors apart and cleaning them. I started a thread on injector cleaning
here. Your injectors will be different but all of the procedures should be the same.
Having the injectors balanced will cost you some money, either to buy or build a tester or to have a shop do the job for you. One of the forum members also offers this service and, I believe, has a good reputation.
Jeremy
__________________
"Buster" in the '95
Our all-Diesel family
1996 E300D (W210) . .338,000 miles
Wife's car
2005 E320 CDI . . 113,000 miles
My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970