What car is it you have?
Why not just convert the WVO to bio diesel?
Its not the injection that is the main problem, its the combustion characteristics of the triglyceride that you are using.
have a read of this

http://www.ncat.org/special/oilseeds_innovations4.php

This was with fresh oil. Not stuff that had been boiled for an extended period.

__________________
Grumpy Old Diesel Owners Club group

I no longer question authority, I annoy authority. More effect, less effort....

1967 230-6 auto parts car. rust bucket.
1980 300D now parts car 800k miles
1984 300D 500k miles
1987 250td 160k miles English import
2001 jeep turbo diesel 130k miles
1998 jeep tdi ~ followed me home. Needs a turbo.
1968 Ford F750 truck. 6-354 diesel conversion.
Other toys ~J.D.,Cat & GM ~ mainly earth moving