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New fuel pump time! I have been experiencing intermittent low fuel pressure when the electric fuel pump is off, and the main fuel pump is the engine driven one. My friend turned me onto the EFII pump for it's simplicity and very low suction loss - where I thought I was getting my low pressure issue from. Out with the old Airflow Performance setup!  Old AFP vs new EFII. The EFII setup comes with an un-servicable filter. I am sure it is something automotive I can easily find on Amazon.  It's going to take a little work to make the new pump fit within the same constraints as the prior pump.  I did not want to disrupt the old pump setup at all. In case I ran into a dead end with the Fly EFII pump installation, I wanted the ability to put back in the AFP pump to go fly. So I needed to make a new support bracket. I drilled two pieces of 063 angle for the sides.  And then I added a .050 top support piece.  The alignment that seemed to work best for me was the pump flow facing forward. I wanted to come out of the fuel selector valve with a sharp 90 degree tube, into the fuel pump, and then a 180 back to the aft end of the boost pump. For this to work, and fit into the existing housing, the output of the AndAir fuel selector valve needed to align nearly perfectly with the input of the fuel boost pump.  The 050 sheet riveted to the side angles.  And the pump drilled and mounted to the support bracket.  I used AN4 (1/4" bolts) on all but one of the mounting points. The reason I used a #10 screw on this was a wiring bundle passed directly under this screw, and the round screw head would chafe the wires the least.  I also notched out the corner of the bracket where the wire bundle passed by.  My first stab at bending 3/8" tubing in quite some time. This is the tube between the fuel selector valve and the 10 micro fuel filter.  Wow, this pic turned out way better than I would ever expect. Looks like a real pro took it!  I needed to get the fuel filters position initially figured out so I could determine how to secure it.  I added a piece of 063 to the left side of the fuel pump to support the adel clamp for the fuel filter.  Nutplate installed out far outboard as possible.  Voila - looks great!  This bend took two tries to get the fuel filter output routed to the fuel pump input.  This was also a somewhat challenging bend from the output of the fuel boost pump to the firewall penetration.   This is where I stopped for my first night - installing some protective rubber on where the wire bundle passes under.  Day #2 on the project! I did not like the positive terminal being completely exposed, so I made a protective cover with some excess rubber tubing.  With everything installed and tightened down, time for the moment of truth - 29 PSI and it kept it - NO LEAKS!  I needed to trim the forward section of the center section cover to accommodate my new bracket.  it took a few iterations, but it is trimmed perfectly.  The final modification was to install a 3/8" adel clamp to support the tube from the output of the fuel filter to the input of the fuel pump. I needed to enlarge the mounting hole from a #12 hole to 1/4" to support the 1/4" threaded holes on the fuel pump. It was a somewhat long run, and I worried slightly about long term affects of vibrations. Test flight was 100% successful! This pump is so much more quiet than the AFP pump! 
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Last Modified: August 13, 2023 |