MSefi.com read only forum (Jan.15,2018)

I need some opinions/advice on my intank electric fuel pump modification I'm working on for my buick. I've already had a sump welded to the bottom of the tank with a "socket" to hold the electric pump & filter sock. I tried my best to design this setup without spending a million dollars and utilizing OEM and existing parts. I'm leaving the original gas gauge sending unit (since it still works) and using the old pickup tube as a return tube. I had drilled a new hole and fitting a 3/8" supply line a few inches away from the sending unit. From this fitting a rubber fuel line (fuel injection rated) will run to the pump mounted in the sump. Now here is where I get a little nervous...the power running to the pump is ran through the sending unit top and along the rubber supply line. It is attached every 2" with nylon cable ties (as nylon is gas resistant) starting from the return line and continuing down the rubber supply line. I tried to leave some slack so the wire does not rip from movements in the tank (vibrations, flexing, etc). I've attached two diagrams to help illustrate this. Does this setup look ok? I even thought about running the wiring through a small 1/8" fuel line (the type used for weed wackers, small engines, etc) that would run parallel to the supply line and secured using ties. I don't know if I'm being paranoid or what. The distance of the wiring is only about 8". Any thoughts would be appreciated. I could also attach photos if needed. Thanks.

I built an in-tank pump for a Triumph Stag, using a locally sourced Ford pump. I went through the same concerns that you are experiencing, eventually speaking at length to a very helpful local EFI shop, who showed me several pump failures
(after 20 or so years use), some where the pump had overheated and burned the insulation off the supply wire. The result
in all cases was the same - car stopped, no fires or explosions. The main thing they stressed was to use cable more than capable of carring the required current, and to secure everthing as you have done. Turning it on for the first time was a bit stressful, but I soon forgot it was there.

This link to the Fuel Injection Forum at Pro Turing might be of interest to you.

http://www.pro-touring.com/forum/forumdisplay.php?f=31

I don't have anything to add to your ideas, but be aware that the hose used for in-tank submersion is a slightly different grade than for external use.

From a fuel hose paper I saved:

"Standard fuel and oil (SAE 30R7) hose is rated for
low-pressure applications at 50 psi working
pressure up to 3/8" size, and 35 psi for sizes over
3/8". This general-purpose hose contains a light
reinforcement, and the rubber materials can be any
compound that is suitable for fuel, oil and vapors."

"Fuel injection (SAE 30R9) hose or MPI (multi-port
injection) hose is reinforced to handle higher
pressures up to 180 psi. It can be used on all
injection systems that use hose clamps. It is not
designed to replace coupled assemblies on fuel
injection systems."

"Finally, for submersible applications such as on the
in-tank fuel pump, only SAE30R10 hose should be
used, because when the hose fails, the pump will
fail. Hose construction consists of low swell
fluoroelastomer compounds in the tube and cover
that resist gasoline and diesel fuel permeation and
aging. Standard hoses have these fuel-resistant
characteristics in the tube portion only."