water in fuel. WVO plumbing problems

[odie]

My car died yesterday. Just cruising along and then nothing. no power at all and then it just died.

I check the in line filter and it was pretty milky looking. I removed the main filter and pour it out. It felt really watery. Diesel has a real greasy/slippery feel. This felt almost like used radiator water.

My system...I have a HIH hose-inside-hose fule line. Fuel line is 3/8 "ice maker" type plastic? hose inside 3/4 heater hose. Feeds coolant from the head into the HIH then back to the water pump inlet.

I appears my fuel line either ruptured or developed a leak of some kind. The fuel line is under vacuum and the coolant hose is under pressure. So I believe the coolant forced itself into the hole/rupture of the fuel line.

I disconnected the HIH and reattached the OEM fuel lines. Then bleed the system best I could. After several, several tries, the engine finally started and ran OK.

Half way home the car started to run real hot. Definitely coolant leaking somewhere. I added some water and made it home OK and parked.

An hour or so later the car would not start again. The inline filter still looked milky and the main filter was still watery feeling. I bleed the system again with no luck. I filled a jar with fresh diesel and put the lift pump hose into it and bleed and cranked a lot more. The engine finally started. I left it at that.

when I get home today I'll drain the fuel tank and blow the OEM lines out. I'll leave the tank strainer out and hopefully any moisture will evaporate.

I'm going to remove the HIH system and take it apart to see what happened. I just made the thing this past weekend.

[JamesStein]

Ice maker tubing? The PVC sort? No way that will stand up to 80 degrees C.

[odie]

Really? I have the veggie oil book "fryer to fuel tank" i think it is called.

Isn't that the type fuel line they use for the HIH heated fuel line? I was sure that was the type line that he used in his book. I got it at Home Depot, 3/8 ID 1/2 OD, it look pretty sturdy.

What kind of hose is used for the HIH system? The book clearly showed a semi-clear rigid plastic type tubing. Compression fittings were used to seal the ends.

[R Leo]

This is precisely the reason I prefer to use electric heating. Free water in your fuel will kill an IP pronto.

[TwitchKitty]

Sorry this had to happen, stuff like this should be fun.

If you are having material failures you may want to spring the bucks for Dana Linscott plans. The time you save scrounging for parts and reinventing the wheel may make up the cost.

When I researched WVO conversions I decided I didn't want to do any of that to my car. Since I currently live in the south I didn't need it anyway. I just run the blend and electric pump back by the tank.

I may add an electric glow plug type heater if I need it.

[odie]

Well, I hope the IP isn't toast.

I got the car to run again last night using a little jar as a fuel tank. So I hope all, or at least 99% of the water has been purged.

The lines and tank will be completely purged before reconnecting.

Why would some water kill the IP? Pure water would have no lubrication but the engine would qui running long before the loss of lubrication could even begin to cause problems IMHO.

Now, if the water was left in the IP system for a little while, I can see rust and/or algae possibly starting.

[R Leo]

Originally Posted by odie

Why would some water kill the IP? Pure water would have no lubrication but the engine would qui running long before the loss of lubrication could even begin to cause problems IMHO.

You're right...a large amount of water all at once would stop the engine. However, small amounts of free water are the worst. The fit between the IP's plunger and cylinder is an incredibly close tolerance and absolutely must have the lubricating properties of fuel oil in order to prevent scuffing of the cylinder wall. Water isn't all that great a lubricant, especially at 2500+ psi.

Additionally, small amounts of water will cause cavitation in the plunger, pressure/delivery valve assembly and injector nozzles resulting in erosion of the metal in those areas.

[odie]

ouch! I hope I have saved the IP. I ran about 3 jars full of diesel through the IP last night. I didn't have a return jar. I just left the return fuel line open and watched it pour out.

I would guess that each jar lasted about 1-2 minutes, depending on how much I reved the engine. I guess most of the fresh diesel ran through the lift pump, filters and IP and then spit back out the open return hose rather than got burned.

I hope that flushed the IP real good.

[Jimmy Joe]

Originally Posted by odie

I have the veggie oil book "fryer to fuel tank" i think it is called.
The book clearly showed a semi-clear rigid plastic type tubing.

That book is old news. I would be real careful before using its advice for an actual conversion. There are much better tried and tested products and methods out there now.
It is imparitive that the products you use can take the heat and are suited for the chemicals used; any old tubing will most certainly give you trouble in the long run.
Think of "From the Fryer to the Fuel Tank" as a sweet, old-school introduction to veg oil. Like 8 track tapes were an introduction to album rock.

[odie]

the hose I used was POLYETHELENE if my spelling is right. What is everyone else using?

Is this POLYETHELENE stuff no good for heated WVO and diesel? The coolant is never going to reach exceed 100'C by much. Water will not get hotter than 100'C without changing the pressure. And the radiator cap is only about 15psi. That is only going to raise the boiling point a few degrees more I believe (it's been about 15 years since I last studied physics).

[R Leo]

Originally Posted by odie

And the radiator cap is only about 15psi. That is only going to raise the boiling point a few degrees more

FWIW, the boiling point of a liquid is raised 3° F per 1 PSI of pressure. But, if the coolant is 100°C it's that temp regardless of pressure.

I suspect that poly icemaker tubing simply isn't a good choice for that application. And, I'd be surprised if it melted; it probably cracked or split at a bend, or abraded where it passed over the edge of a structural member in the car.

[coachgeo]

Do you have an intank coolant heat exchanger? If so that may be where your leak is. Try these guys as a source to track your problems down.

Maui Green B. Board SVO forum

Several guys in there have MB diesels converted.

[odie]

3'F per PSI...then 257'F (212+3x15) is the max temp the coolant will ever reach before it boils. Once it starts to boil it is no longer water but steam. Once the coolant reaches 257'F the PSI of the cooling system is 15psi and the radiator cap will start to vent or "boil over" as it is also called. At that point melting fuel hoses is not your real problem or concern anymore. You've got bigger problems. Steam is hotter than boiling water, but is much less efficient at transfering heat.

The HIH is the only thing the car has. I run 50/50 blend in the stock tank.

The Poly hose is completely encased by the 3/4 heater hose. All the way to and including the hose clamps. There is no expose poly tubing, not even at the very end. There are no sharp bends or anything. It is possible that the poly hose might have gotten kinked while assembling.

I'll be removing the HIH after work today and see what I find.

[TwitchKitty]

Originally Posted by odie

The HIH is the only thing the car has. I run 50/50 blend in the stock tank.

Did you ever try running the blend without heat? I am under the impression that I could run that 50/50 blend at really cold temps without any heat.

Quality of oil is an issue. We say WVO but it can mean anything. If it is oily and dirty it is WVO. I am going to start filtering my oil after it sits overnight in an old spare refrigerator. That way anything that gels down to about 33°F will get separated out.

[odie]

All my first trials wre unheated, 100% stock car & filters.

I started with about 25-30% and went to 50% real quick.

My current blend is 50/40/10....WVO/Diesel/RUG

WVO is filtered to 5 micron, nominal rating, at room temp after settling.

Cold starting was OK. at around 40'F-ish I would have to cycle the glow plugs a couple times and keep my foot on the "gas" after starting for just a little bit.

When cold out (south texas cold that is) the idle was sometimes a little rough...that is why I am adding HIH to help the IP go to a higher % WVO. I will also add a boost pump, mainly to help with feeding the lift pump at higher % WVO