bustedbenz - what symptoms did your car have that caused you to have your injectors worked on?

Does anyone have experience with telling the difference between injector nailing and other noises such as sticky lifters?

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1986 300 SDL, gray on black, #14 head, 180K miles
1982 300 CD, silver on palomino, 290K+ miles [sold]
1980 300 SD, white on palomino, 500K+ miles when retired [uncle's car - inspiration for the above]