'84 300D, 385K mi. WVO the past 25K mi. 5u final filtering (has a functioning boost pump). I slowly lost power over a 1K mi period. Did a valve adjust, fuel sys. complete flush-out, filter changes and new monak injectors. Checked for air leaks into fuel sys., none. Checked Turbo waste gate was opperation correctly, yes. Ran straight Dinodiesel the past 20Gal with a bottle in injector cleaner (for 50 gal.) Ran a qt of injector cleaner straight. (this isn't the diesel purge you have, but I just got some and haven't used it yet.) Cold Compression read, 400, 305, 400, 340, 380.