I'd stop if it's straigh vege oil... Do you run a 100 series with an electronic fuel pump?
There are a number of issues to consider...
1. with SVO engine components can be gummed up and can destroy piston rings and reck havoc on valves etc.
2. IP will get gunked up - could nail the timing control valve, but even if it just gums up the IP internal filter, you pay £360 for a strip down and recalibration
3. If you oil is not brand new you need to filter down to 5 micron
4. The 100 series has a tempreture sensor on it's IP, this triggers a heater on the fuel filter. Problem is that this is set up for Dino diesel, different types of vege oil will go solid at different tempretures.
5. The viscosity difference between oil and diesel even when hot will be significant. Electronic pumps are sensitive to this.
Diesel Bob's is a good source for info...
http://www.dieselbob.co.uk/vegetable.asp (page down to Denso V4/V5) Electronic denso pumps gets 4 our of 5 stars for perfectly made biodiesel, but only 2 out of 5 stars for vegetable oil. Savings would soon be wiped out if you get any serious damage.
From what I can tell if you were able to purchase or make very good bio you'd be ok! Problem is that commercially made bio is not regulated and therefore often variable quality, particularly in the wash process. Glycerine, Methanol or Soaps will cause problems. If you want to talk more about bio, give me a shout!