I have seen a lot of conversion diagrams showing wvo going through the lift pump and these diagrams only show two 3-way valves.
Do all these setups have the wvo going through the secondary diesel fuel filter?
I was think of having a 3-way valve before and after the lift pump so I could use the benz lift pump but not use the secondary diesel fuel filter.
Has anyone done this?
I could also bypass the lift pump and have the auxiliary pump push the wvo to the injection pump.
The 2 setups I was thinking about would look like this.
WVO tank>auxiliary pump>wvo filter>FPHE>3-way valve>lift pump>3-way valve>injection pump>3-way valve>wvo tank
WVO tank>auxiliary pump>wvo filter>FPHE>injection pump>3-way valve>wvo tank
Is everyone that converts the w123 benz's sending their hot wvo through their secondary diesel fuel filter?
I know it would cost more to buy more valves but I'd like to have the wvo system separate as much as possible.
I would install a delay timer on the return and have heated injector lines.
Thanks for any info or advice.
My '87 300SDL MB has only two (HydroForce) valves. The difference is the return valve is a 4 WAY valve. It allows the D@ MB lift pump to continue pumping D2, but the 4 way opens and sends to directly to the D2 tank. When running on VO, the return VO is goes to a "T" placed the VO IN PUT line and before the VO pump. I didn't like the D2 lift pump be "dead headed" pushing against its self with the 3 way return valve. The part number for the HydroForce 4 valve is SV08-43-0-V-00. I paid $85 less the hose connections. Google HydroForce for dealer nearest to you.
That's a good idea about letting the lift pump continue to pump D2 and send it back to the D2 tank.
So I guess you don't use the D2 filter?
Do you see any problems with using the lift pump and adding 2 more 3-way valves so you don't use the D2 filter?
I will have a heated wvo filter installed.
The D2 filter is only used for D2. The VO comes from the heated VO fuel filter to the supply (3 way) valve. When I switch from D2 to VO, the supply (3 way) valve sends heated VO to the IP and at the same time the 4 way RETURN valve sends the recirculating D2 back to the MB D2 tank. The MB lift pump continues to pump through the D2 fuel filter. I use the Bosch VW fuel filter #0 130 000 020 70 ($6) and Jetta # 104 540 045 85 ($44) oil heater head. An added benefit of using the VW /heated filter setup is when changing VO filter. Install the new DRY filter into the unit. It can be filled with new VO by adding "T" and small ball valve (between the filter and valve) to the VO supply valve. Assuming the VO has an electric fuel pump, the ball valve is opened and the electric pump is turned on. The VO will be pumped into the VW filter pushing all the air out through the ball valve. I place a clear plastic soda bottle to catch the VO as it spills out of the ball valve. When a solid stream of VO and no air bubbles comes out, close the ball valve then shut off the electric VO pump. No mess, quick, clean hands and clean engine compartment. Sorry, but I do get a little wordy at times .....