What happens if you place diesel in the wvo tank? Bubbles?

I'd say its easier to suck air than the thich wvo. Look for leaks before the lift pump.

FYI, I run a one tank system on my cummins. Up to 80% wvo/diesel blend with no heat. Ambient temp here is around 65-75f. Any cooler, I just put more diesel in. 50/50 down to 40f.
OK so far 10K miles. Idles REAL slow 'till it warms up though.