First of all, what is blowzy? You used the term twice so it is not a typo I assume. The idle response to throttle sounds normal- maybe just a tad slow. Can't tell much at idle, engine must be under load.

Need to know more about your veg system. Single tank, dual tank? Need more info on that metal mesh filter with the drilled holes. Sounds strange. Any pics? Having to clean the filter every 300 miles suggests your fuel is not well filtered and may be a clue to your problems.

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85 300D turbo pristine w 157k when purchased 167,870 July 2025
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked