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Installing An Electric Fuel Pump in a Pre-1962 Car

September 27, 2010 | Troubleshooting & Repair

Three different installations by Barry Lee Brisco, Leo Hudson and Jim Neil

 

Here are three approaches to installing an electric fuel pump in a pre-1962 car (1962 and later cars see this article). In each case, the pump is located behind the floorboards so it is completely hidden yet close to the ignition for easy wiring. The pump is used as an aid in starting the car when it's been sitting for days and the fuel has evaporated from the carburetor float bowls (modern gasoline evaporates more easily that it did in the 50's), in case of vapor lock on a hot day, or as an emergency back-up if the mechanical fuel pump fails. A simpler and less expensive alternative is a priming bulb in the engine compartment, but that doesn't provide any back-up capability and doesn't look "period", if that's important to you. Another alternative is the Precision Matters "Primer Reservoir".

 

Barry Lee Brisco: I elected to mount a Pierburg electric fuel pump in the center area behind the floorboards and directly below the fuel petcock. See the two photos below. This pump will operate in either the horizontal or vertical position. The pump outlet is at the end with the terminal connections. It's a bit more difficult to work in that confined space compared to the more open location behind the passenger footboard that was used by Jim Neil and Leo Hudson (shown farther down this page). However, using the center location meant that the hole drilled for the pump mounting clamp doesn't have to pierce an exterior chassis surface and the additional flexible fuel lines don't have to be routed through the sharp-edged oval opening in the vertical member.

 


Photos by Barry Lee Brisco

I used a three-position toggle switch from Zim's to control the pump, wiring it up directly to the ignition using a bullet connector. That switch has an "on", "momentary", and "off" position in the center. The hot wire is connected to the center post of the switch. For an additional fuel filter beyond the stock filtration, I use a metal filter in the flex line beneath the car that runs next to the transmission.


Placement of pump & wiring
Placement of pump and wiring behind floorboard. Photo by Jim Neil.

Jim Neil: In a T2 / T5 car, an electric fuel pump fits nicely under the floor board on the passenger side. The Walbro pump comes with the mounting bracket shown in the photo. Run a fuel line from the fuel cock with a filter to the pump input, and one from the output to the tunnel fuel line, and that's all it takes. The pump is controlled from a switch under the dash to the right of the steering wheel. When the pump is off, fuel will flow through it without any restriction.

[Editor: Al Zim notes that it is better to use a metal fuel filter rather than the glass or plastic type and to mount it under the car at the rear where the fuel line runs next to the transmission: not in the engine compartment. And Bob Slayden observes that "the fuel lines be protected with a second layer of fuel hose where they pass past the raw edge of sheet metal in the tunnel or rerouted to not be pressed against the metal edge to prevent them from being cut through."]

Leo Hudson:  For electrical connections you need to select terminal on the ignition switch that has power only when key is in the on position. For early switches with screw type terminal connections this would be terminal #54 (provides power to radio) or #15 (provides power to coil). On latter switches with bullet type terminals there are extra unused #54 terminals and one these can be used. Also on these latter switches there is an extra #15 that can be used. The wire from ignition switch goes to one terminal of toggle switch and from the other terminal of toggle switch you run a wire to the fuel pump's + terminal, I elected to put a inline fuse in this wire. At the fuel pump I ran a ground from the pump to screw that mounts pump to body.

When starting, I generally run the pump approximately 15 to 20 seconds if car has not been run in several weeks. You usually can hear a change in noise as the gas lines and carbs fill. I also leave pump running when car initially starts until it is running smooth and then turn it off. I have also used pump after a long drive in hot weather and say you stop for lunch and there might be a chance for vapor lock or gas evaporating from carbs.

All photos below by Leo Hudson







Sources for Parts Described in This Article

This list of vendors, in alphabetical order, is not necessarily comprehensive, and additional companies may also offer similar products. Note that where possible, links are provided directly to a specific product page if available.

NLA: Walbro (NLA 108 005 00) and Pierburg (NLA 108 005 01) electric fuel pumps

Zim's Autotechnik: Pierburg Low Pressure Fuel Pump, Three Position Toggle Switch

4 Comments

Dsc 5675
Bill Lawless
August 27, 2013 at 12:48 PM
Just an FYI:<br />The fuel pump NLA advertises with an attached filter they ship you [i][b]without[/b][/i] the filter, still cost the same though:<br /><br /> Electric Fuel Pumps, 6 volt or 12 volt<br />These are US-made low pressure pumps designed specifically to run on 6 volts or 12 volts. Shape and design is perfect for Porsche 356 Cars, mounted in the floor tunnel or under the right hand floor board area. [b]Pump is 175 mm long including attached filter[/b].
Dsc 5675
Bill Lawless
August 27, 2013 at 12:56 PM
?
Dsc 5675
Bill Lawless
August 27, 2013 at 12:48 PM
Just an FYI:<br />The fuel pump NLA advertises with an attached filter they ship you [i][b]without[/b][/i] the filter, still cost the same though:<br /><br /> Electric Fuel Pumps, 6 volt or 12 volt<br />These are US-made low pressure pumps designed specifically to run on 6 volts or 12 volts. Shape and design is perfect for Porsche 356 Cars, mounted in the floor tunnel or under the right hand floor board area. [b]Pump is 175 mm long including attached filter[/b].
Dsc 5675
Bill Lawless
August 27, 2013 at 12:56 PM
?