I suggest you to heat up your biodiesel if you run 100 % of it.
it will allow you to be near the viscosity of the diesel fuel even in winter with a "standard" tune (0.95 or more for sure) for your injection pump.
the injectors must open at bigger pressure too if you run biodiesel it's 155 bars stock and i would say at least 10 more bars for biodiesel.
If you want to start with pure biodiesel you should install a heater in the intake line of the pump or reduce the percentage of biodiesel (so to make a mix with fuel) to reduce the viscosity.
the viscosity is very important !
the VE pumps are very strong but are designed to run with diesel fuel not vegetable oil
they can break quite easily in winter.
viscosity create more stress on the moving parts and crappy atomization in the pre chambers and glowplugs break because of the localized stress during the bad combustion (don't forget the combustion starts in the prechamber where the glowplug is.
you always will have problems with biodiesel in winter if not heated up enough.
heat up your fuel in any case.
bad injection pattern create pinging marks on the pistons like on a gas car....the rings don't like it.
