AltFuel 3B WVO: Help! Return fuel line inadequate!

[doctorb]

So my system is in place. 2 tanks, heated all the way, two 3 way valve, one as a fuel selector, the other directing the return flow from the fuel overflow to either loop back to the engine or to T into the veggie line.

Problem.

I'm getting zippo return flow from the overflow line. I was expecting to use that as a purge to get all the veggie out of the line before shutting the truck down, but I'm getting no flow except a tiny dribble. Any ideas why this is happening? The pump is supposed to be putting out a liter of fuel a minute. Where is it going?? Thanks for any help you can offer.

 

[hes21]

What pump is supposed to be putting out a litre a minute?

An additional one on the veg tank? If so, it may be trying to pump a litre a minute but the inline 3b pump won't pump more than what is usual. If you aren't using all your fuel in 50 minutes, don't worry.

I haven't converted my 3b yet, but had read that most people don't bother with returns. If it's such a small ammount just let it go back into the fuel pump as usual. It can't add that much time to your purge.

Cheers,
Hamish

 

[doctorb]

The inline pump supposedly puts out that much, but I'm questioning the truth to that now. Are other people with 3Bs just not backpurging? Just leaving veggie in the line? Doesn't that really suck for cold weather?

 

[FrankJames]

Nah, depending on how you have it plumbed, you only have a couple of inches of hose with cold veg in them. As long as the engine is up to full operating temp, the latent heat in the heads and IP will heat up that tiny amount of cold veg plenty hot enough to behave as it should.
I dont know much about B's but my 2H doesnt have a return and it is just fine.

 

[dreko]

Hey Doctorb,
where are you located? I'd love to see how you've got things hooked up.

 

[doctorb]

I'm in Kenai, Alaska... probably not the most accessible location for most folks =).

New thought here. Can I use my bleed line off the stock fuel filter as a purge line? I'd be worried about it being too pressurized, but if I could some how contain the flow and keep everything from leaking, it would make my purge time much much shorter.

Currently, I have a bleed valve on the input side of the filter... was thinking if I could put the bleeder valve on the output side of the filter, purge times would be even better.

I was thinking a solenoid rather than a 3-way would be the best option for this. Just trip a switch to open the bleeder valve into a T into the veggie supply line when I'm ready to shut 'er down. Thoughts?