I am stuck and looking for some advice. I have a 6L with a Mallory 110FI Fuel pump pulling vegetable oil from a second tank. I am using it with a regulator to push the oil at 65PSI. The unit was running great all winter but since it warmed up has been blowing fuses after about 30 minutes of running. I checked all of the wiring, ground, relay etc. I ran 12 gauge wire again. Nothing.
I am wondering if the pump has gotten too hot and is toast or if there is something else I am missing. I am pulling through a heated 5 micron filter. The regulator bypass back to my tank. It has worked great for about 6 months though the loadness of it drives me nuts.
I will check the amperage draw tomorrow. Mallory says 12amp draw typical. I have a 30amp fuse in place and a 50 amp relay.
The Mallory is not up to the task of pumping WVO - especially cold oil.
The only decent option is the FASS HPFP, but even it is known to have a relatively limited lifespan in VO service (mine have run 40-60k miles). FASS will rebuild them for about $125 (usually ) when the motors finally burn up.
Hopefully, BFT/Vegistroke - forum sponsor here (previously DFA) - will make a stand-alone version of their superior-to-FASS Scorpion Pump soon... (it is USER rebuildable! ) Pumps and Parts - Biofuels Technologies
I recommend 'looping' that return back to the suction-side of the pump. This will reduce the load on the pump dramatically and will help you retain any heat you've added to the oil at this point.
FWIW, alot of folks were using Mallory and Aeromotive fuel pumps when I did my conversion - after talking with several of them and realizing they had a huge pile of junk ($400 ) pumps between them, I decided to just use a stock 7.3 fuel pump. At least it had a no-questions-asked warranty at local autoparts... I ran it without any issues for the first 70k miles on my conversion. This pump does not like restriction on the suction-side though - I'd recommend putting filter(s) on pressure-side (post regulator, so ya don't filter the fuel but one time ). Just use a screen/strainer pre-pump to protect pump from a pine needle or leaf that may fall in your tank while filling.