Biodiesel has more "solvency" than dino. May have just opened up an air leak. You can use a rag around an air hose in the tank filler neck to create a few pounds of positive air pressure and see if you can find a wet spot in the supply line somewhere to confirm or eliminate this possibility.
Might also try a double dose of injector cleaner and drive it like you stole it for an hour or so and see if it will clean up.
The 12v engine should run like a champ on biodiesel.
I actually just had the injector cleaned and pop tested and they were all A -ok. Im still going to try the injector cleaner just in case. The leak I havent looked for I will check it out.
My truck only does it randomly though. Not all the time.
My truck was a gasser for 99% of its life, I have changed the fuel filters twice on 1 tank of bio. Im thinking it might be the pickup tube from the sending unit. Im gonna drop the tank this weekend and tear it apart and see what i come up with.Bio is a fairly strong solvent. It will loosen all the dino gunk in the tank and promptly plug up your fuel filter. Course you already know that, I wonder if the pickup screen in the tank is plugged with dino gunk? SLICK CONVERSION congratulations. If the in tank screen was gunked up, you could probably find out by teeing into the suction side of the lift pump and checking for vacuum. Should have virtually none.
You did change the fuel filter at least once AFTER the bio right?
o and thanks