Jezi, you may have "solved the veg oil problem" but the motor doesn't agree.
During the winter #1 diesel is added to #2 diesel in cold areas so the
fuel will flow. (#1 contains some kerosene.) I suspect the veg oil is
now Crisco inside the fuel filters etc. and that's why no fuel is at the
injectors. So all must be set back to its "default" state.
First, if your "cables" are steel pipes, put the steel fuel pipes back
on to the injectors and DON'T over tighten their nuts - these are
compression fittings and over tightening will ruin them. Just firmly
snug and if it leaks make it a bit snugger until it no longer leaks.
Think, about 10 ft lbs, not more. But if your "cables" are, in fact,
electric wires see paragraph about glow plug relay below.
There's a hand primer pump down at the small clear plastic, secondary
fuel filter. It sticks up and has a black plastic cap that unscrews so
you can pump it (wear latex gloves). Pump a bit and watch the clear
plastic fuel lines for bubbles, or any movement of the fuel in them. The
clear plastic secondary filter element ought to be the color of wet
wood. If it's very dark it probably ought to be changed. The fuel also
goes through a primary spin on metal filter that's behind (aft) of the
power steering pump. Replace it too if the secondary filter is
questionable. Then pump, pump, pump the hand primer to move fuel to and
fill these two filters until all air bubbles have been expelled back to
the fuel tank.
Alternatively, you may have to direct an electric space heater (not a
torch) at the lower left side of the motor to liquefy the fuel inside
the filters and injection pump. Plus hand priming.
Finally, on the left fender is the glow plug relay. It has a black
plastic cover that slides UPward to reveal an 80 amp fuse a/k/a fusible
link. It should be intact, if it's not the motor will not start, period.
You ought to carry a spare link, they cost about $1 at M-B dealer or on
Starting diesels in very cold weather, especially worn ones, is
difficult using diesel fuel so don't try to push the envelope with the
veg unless you absolutely KNOW that it won't gel at your location's
overnight temps. Base winter case ought to be diesel unless you KNOW the
veg will flow.