I've recently been noticing that the my car (85 300td) seems to lose power. This is usually happens when I'm accelerating (slowly) and then is seems like the turbo disengages, and then car gets sluggish, if I give more throttle the turbo kicks in after a second of hesitation and then the car runs well. The problems also doesn't seem to happen under heavy acceleration. A few background things you should know: I live in indiana and it has been cold (high of 20f) lately, and maybe the car hasn't had a chance to warm up enough. I recently installed a WVO (frybrid) kit on the car, but I have yet to actually run VO in it, and this happens when running on diesel (but the car did run fine after the conversion until a week ago). Also When installing the tank I cut a vacuum line beneath the rear trunk area, there is a major leak now, but enough to operate locks (slowly) when engine is running. Thanks in advance for your help.

fix the leak(its not directly related though)

cold air is good for engines

have you removed and cleaned the banjo bolts, adjusted the ALDA unit, and or inspected your turbo for axial play and ease of spin?

also.. last time fuel filters were changed

I wouldn't be surprised if you created an air leak in the fuel system someplace.