i know its only my second post and yes i have used the search button my problem is and i dont know if it is related to what i have been doing the last two fill up i have done a 50%50 mix of new veg oil and fuel the first one the van ran with no issues the second one on start up getting lots of black smoke and it is hesitant to rev is ok when warm but today when i was in it about 2500 revs its feels like it is strudling for fuel the sedimeny filter has been cleaned out and has had a fuel filter about 4 months ago al this is on a p reg 300 tdi auto disco with 170000 miles on it the only engine mods so far is a de-cat single box system and the erg blanked off and has the fuel pump screw turned up a bit any ideas would be greatfull