Purpose of the purge solenoid??

[01green73]

Is it only used when switching filters, or every time you switch to WVO or back? What happens if it is not used?

[leongriffin]

In a typical Ford PSD WVO system; the purge solenoid opens and allows the diesel to purge the WVO from the engine. This is done during the shutdown procedure either manually or automatically so that the engine is ready for cold starting. Starting a cold engine on cold WVO is bad bad bad.

If you would like to see a complete Ford PSD design with the electrical schematics for an automatic WVO controler check out the forums at the attached link.

Leon
WVOdesigns.com

[jstrauss]

You need a seperate purge solenoid so that when you switch from veggie to diesel, your return line does not send veggie back into the diesel tank.

[redtopman]

Leon,

What is the purpose of back to back checkvalves as in the vegistroke system. They install an additional check valve beteen the head and the stock check valve for 99 up engines. Just wondered why?

[01green73]

I know that you don’t want WVO in the diesel tank. Is it ok to get diesel in the veg tank? What happens when they mix? Is It like oil and water?


Has anyone ever set up a 7.3 this way?: four (4) check valves (one on each end of both heads) and no purge solenoid? How long would it take for the veg in the heads to burn up at idle after you switched back to diesel?

I haven’t seen the later design yet, but maybe there is more fuel in the heads than I imagined so it would take longer to purge than I think.

Thanks for the info, Travis

[redtopman]

Yes it is ok to let diesel go into vegi tank during purging. In fact some papers at vegistoke recommend a mixture of small amounts with of diesel with the WVO. I don't know how good the mix is.

I haven't seen a design like you suggested yet and I don't think I will. Purging is necessary to insure all the WVO is removed. As I understand it also removes air.