Hello all. Today I had my first problem running on VO that I can't figure out. My driveway pulls out onto a 55 mph road, and I usually switch to VO after 5-7 miles when the engine heats up. At about mile 14, I hit a stoplight, and today my engine died as I pulled up to the stop. I switched over to diesel as the engine died (thought I may have run my VO tank empty, not the first time, i'm sad to say) and it took about 2 minutes of trying before the truck fired up again. I finished my commute on diesel and when I got to my first appt, I checked my VO tank and there was still about 15 gal in the tank (which is about what I thought I had). The rest of the day, I ran on VO and no problems. Any ideas on what may have happened? Is the a sign of bad things on the horizon?

It was really stormy/rainy toady, but I don't think that should matter.

thanks

as always
peace and love
billyO

air bubbles or plugged filter come to mind

Scott - Starting to plug the filter was my original thought (filter is just starting to pull 3-5mmHg vacuum when climbing hills first thing in the am), but I thought I was just switching over prematurely now that it's getting colder.

Air bubbles? Any idea how this happens?

thanks again

as always
peace and love
billyO

Billy, is your onboard filter heated?

240- If by onboard filter you mean my VO filter, then yes, it's coolant wrapped, if you're talking about the diesel filter, then no. I don't think the filter was the problem because when the engine started to stall I didn't notice my vacuum gauge indicate that I was pulling much (if any) of a vacuum.
thanks for the help
as always
peace and love
billyO

How large is your veg tank and where is the fuel pickup located in that tank. I have had problems with pulling a slug of air into the fuel pickup during braking, acceleration, or on sharp turns when the fuel in my 2ft X 2ft X 4 ft 100 gallon bed mounted farm fuel transport tank gets low. I am now reworking one of these tanks so that the fuel will be drawn from about a half gallon sump in the bottom rear center of the tank to try and eliminate this problem.

Hey all. Had the problem again today and found out that I have a leaky fitting between the VO filter and the looped return T (I saw bubbles). It seems that I'm sucking air, enough to cause problems when stopping for brief periods while running on VO, but not enough to cause the engine to die when running at highway speeds. Looks like I've finally got the motivation to change my VO filter set-up like I've been planning. I'll try to post before and after photos if interested.

Thanks again for all the suggestions and help.

as always
peace and love
billyO

When my system was first in and plumbed to pull fuel through the filters, I would get an air buildup in the diesel filter head that caused stumble / stalled when turning a hard left corner, at street speeds. The fuel level tilted and the air pocket dipped lower on one side and the pump sucked a big gulp of air... stumble. At steady speeds level street levels evened out and the pump would be constantly sipping a good mix of fuel and air, not what you want, but enough fuel to not cause the problem. All those bubbles, ah, the bubbles, the nightmare of pulling fuel... it's much better to push liquid fuels. So all got changed when I re-did the plumbing to push fuel through the filters. All bubbles have gone away, and stayed away.

Scott - Thanks for the post, but my system is a pusher too. The bubbles are VO leaking out when the system is pressureized.

quote:

Originally posted by billyO:
The bubbles are VO leaking out when the system is pressureized.

If the leak is in a pressurized area, you can't be sucking air, you simply get a VO drip.

SunWizard - Yes, I agree that a drip would happen when the system is pressurized, but when running on diesel with a looped return and a leak, there would be no pressure in the system anymore, and the fuel running through the loop would pull a small vaccum from the VO line that runs between the VO filter and the looped return T.

as always
peace and love
billyO