Tech article by Ed Wilbur (eds66bronco)
I wanted to provide good clean fuel to my efi project and to be sure I had fuel at any angle I might find myself at. I looked into all the different options for accumulators and decided that like everything else on my bronco, half the fun is making it myself. So off to the parts store I went. I started with looking at remote oil filter brackets and ended up with the Fram HPK2 with a Fram P4105 filter. This thing looks like it would hold well over a quart of fuel in the event my tank pickup tube sucked air. I fill the accumulator with a carter lp pump mounted near the tank and my hp is the airtex E2000.
Once I got home I looked at the way it worked and layed out how I wanted my hoses to route. I was using braided lines and AN fittings so I had lots of options. The input and output bungs were 1/2 npt so I ordered 2 adapters for each one to step me down to a 6AN fitting. I also used a 6″ piece of 1/4 npt threaded pipe for the pickup tube. A 2″ brass pipe with 1/8 npt threads on each end and a 6AN fuel gauge adapter was used for the fuel rail return and accumulator overflow back to the tank.
Look at the bracket assembly and locate a spot to drill and tap for the return. Make sure to drill to the inside of the seal area. Tap just far enough in with the 1/8 npt tap that the threads will seal but not so far as to have the pipe extend through the bracket. Attach the fuel gauge adapter to the top. I used teflon tape for all these connections. If you do use it, make sure that none is extending past the end of the threads where it can come apart and get into the fuel system.
Now install the steel threaded piece that the filter threads on to. I coated the threads with lock-tight prior to installing it. Next you need to tap the inside of this for the 6″ 1/4 npt pipe that will be the pickup tube. Once this was tapped I used some teflon tape and threaded in my pickup tube. To get the correct depth for your filter, insert a dowel into the bottom of the filter and put a straight edge across the gasket. Mark the dowel and transfer the measurement to the pickup tube. I subtracted a 1/4 inch to account for gasket squish and so the tube didn’t bottom out in the filter.
I decided to mount mine on the frame in front of the spring hanger. I would have located it up in the engine bay but just could not find the space. I bent up a skid plate to keep the filter protected. To prime the system, Disconnect the hp pump and run just the lp pump until you hear fuel flow back into the tank. This will provide the hp pump with fuel so it doesn’t cavitate and burn up trying to prime.