Ahh yes, the inevitable air leak...
One of the big issues with veg oil systems, and one that will leave you on the side of the road in short order.

Something is not tight enough or restricted, causing you to draw air into the system. I assume you have new filters on there, those will plug real fast with a poorly filtered batch of oil. What kind of fittings are you using where your hose clamps are? Are they multi-barbed, or just rubber over metal? Low quality connections will surely give you trouble. This is a likely place for a leak. Even if you would not normally draw air into the system at one of these points, if there is any kind of restriction at all, air will get sucked. You do need 3/8" id hose at a minimum. Is the oil hot and thin, or cold and thick?

How far are you moving the oil? Are you making the stock fuel pump do all the work? You might have to reconsider that...

If you just can't find your leak, temporarily running clear hose lengths in place of your fuel line can help you spot it.

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