Originally Posted by GREASY_BEAST

Here is how my WVO system works on the diesel side (the path a particle of diesel fuel would take as it goes throught the system):

diesel tank > 6 port solenoid > stock lift pump > 6 port solenoid (again) > stock diesel filter > 3 port solenoid > IP > 3 port solenoid > diesel tank

here is how it works on the veggie side (the path a particle of veggie would take as it goes through the system):

WVO tank > 6 port solenoid > stock lift pump > 6 port solenoid (again) > Heat Exchanger > veggie filter > 3 port solenoid > IP > 3 port solenoid > WVO tank

to clear things up, the fuel system uses the stock lift pump on both fuels, and the 6 port and the first 3 port are wired to operate together, and the second 3 port (the one after the IP) is on a seperate switch for purging. Essentially, instead of buying 2 lift pumps and removing the stock one, I just bought a 6-port and set it up to run both fuels on the stock one. I don't think the problem is with the conversion because except for the fuel going through the solenoids, the diesel side of the system is basically stock. The only difference is that I T-ed the low pressure injector return lines into the IP return before the 3 port. I have checked and double-checked all my connections and I am pretty damn sure that there isn't an air leak anywhere.

I really think it could be the IP... something tells me that the fact that I have to floor it to start on diesel suggests that it is an injection problem, not a pre-IP problem... I know the IP is designed to operate with positive pressure, if the lift pump is bad could this problem happen? Although, the fact that it runs on veggie just fine pretty much eliminates this as an option.

In conclusion, I really really don't think there are any problems with the fuel system before the IP.