I'm running heated WVO from a 2nd tank. At first, I used a Facet boost pump to help out the stock pump. After eating up two stock pumps and one boost pump I figured the force-feeding the WVO was damaging the stock pump.
Now I have what is supposed to be a more robust boost pump and a fuel pressure regulator set at 1psi immediately prior to the fuel solenoid valve. That way the factory pump isn't hurt by force-feeding.
Diagnosing some fuel supply problems today, I found the Facet pump is only putting out 20 gallons per hour, not the 32gph as specified.
I also called Carter, the manufacturer of the stock fuel pump. They said the factory pump is not designed to be force-fed and it is NOT designed for WVO. No surprise there. He said it is rated for 25gph at 56psi.
I like the simplicity of having both the diesel and WVO going through the stock fuel filter. But, the fuel pump issues are eating my lunch. What about swapping the stock fuel pump for a Mallory 110FI? This pump puts out three times the flow rate but about the same pressure. Can the filter housing mounted regulator handle it?
Otherwise, I'm leaning toward going with a Vegistroke style system to use completely separate pumps for the diesel and WVO systems respectively.
How many are using the factory fuel pump without any boost pump? Maybe that is my problem. I'm helping it too much!
One way or another, I've got to get this thing working better.
Update: I bought a new Mr. Gasket boost pump rated for 35gph at around 3psi. But, in doing some online research I found that the Facet pump I had on there has an internal 70 micron screen. Guess what? That screen was nasty.
I cleaned it out but still didn't get quite 30gph though the book says its rated for 32. This was pumping diesel (not WVO) from one container to another, not through any filters.
The Mr. Gasket pump timed out to a solid 35gph, only slightly less going through my filters. I currently use a regular automtive oil filter as a pump pre-screen plus a couple of 10 micron Luberfiner filters. My ultimate plan is to go to a 1 micron filtering in the shop and a 2 micron on the truck for a final polish.
I'm also going to wrap the filters with a heater hose coil ala Dana Linscott's design. My plan is to Tee off the 3/4" coolant hose for a side loop around the filters. This will maintain the excellent coolant flow rates with the 3/4" hose but send some coolant for heating the filters. That's a lot of oil that would be cold at startup, regardless the temp in the tank.
I'm going to keep the Gold round style Facet pump on the truck for backup in case the Mr. Gasket croaks on the road.