Electric Fuel Pump Question

don's 37

don's 37

Senior Member
Hello again. I was just reading some past posts about installing an electric fuel pump. I understand that you need to install one as close to the gas tank as possible and also read that you can turn it on and off when needed. I read where you can turn it on before starting your engine to begin priming so that it saves wear and tear on your starter. So my question is, the electric pump will actually push gas "threw" my mechanical pump and into my carb? It will actually push gas through the valves in my mechanical fuel pump without damaging it?
 
It will "push" gas through the mechanical pump just fine, the problem I have now is the mechanical pump won't "pull" fuel through the electric pump. So I'm plumbing a bypass around the electric pump with a one way check valve. I'll post pics after I get it working.
 
I have fitted one to my 34, rubber mounting it near the steering box on the chassis rail with a switch under the dash a good idea is to fit an idiot light so you remember to switch it off, some pumps pull and some push so where you mount it depends on the pump type always fit an inline filter before the pump some come with an integral filter. I switch it on until the ticker ticker sound slows right down turn it off and start as per normal if you leave it on it will push fuel out of the mechanical pump seals, easy as works great good luck.
 
With an electric pump it is a good saftey idea to install an inertia switch to shut it and the ignition off if you get bashed. They can be had at wrecking yards for less than 5 bucks.
 
I'm going to install an oil pressure switch for an electric fuel pump. Below 7 pounds electric fuel pump is off. There should be enough gas in the carb to start up without the fuel pump and reach 7 pounds oil pressure.
 
I used a 3 1b Carter 6V electric fuel pump on my 8BA for starting only and had to install a bi-pass valve, as the mechanical pump wouldn't draw enough fuel through it above about 35 mph. Afterwards I found out I should have used an Airtex pump which doesn't have the restriction.
 
Here are low pressure (2.5-4 psi) pumps so you don't need a regulator and you can run the pump continuously or just when you need it which is what I do. Mechanical pump will pull fuel through them just fine.

For 6 volt it's AirTex 8902 available here: http://motors.shop.ebay.com/eBay-Mot...0.l1313&_rdc=1

For 12 volt it's AirTex E8016S available here: http://www.ebay.com/itm/AIRTEX-E8016...880d0d&vxp=mtr


Here's my installation:

Fuelpumpelectric.jpg


This installation doesn't even require drilling a hole. That hole where the bracket is bolted on is already in the frame. This is a positive ground installation so the pump positive wire is what's grounded and the negative comes from the switch.

Here's the switch I use to turn it on momentarily when needed.
IMG_2826.jpg


It's the toggle switch on the right. The left one is for the interior lights. The switch is a Radio Shack micro-mini SPST switch here: http://www.radioshack.com/search/ind...st+switch&sr=1
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Henry, is that a typical on/off switch or a momentary toggle switch that springs back when you remove your thumb? Soon I'll be installing the Airtex pump and was thinking that a momentary toggle switch might be better and that way I wouldn't forget and leave it on if distracted by something else.
 
On mine the pump gets it's power from the ignition switch, then to a toggle switch to turn on the pump. With the ignition switch off the pump will not stay on, in case you forget to turn off the toggle switch.
 
Strick said:
Henry, is that a typical on/off switch or a momentary toggle switch that springs back when you remove your thumb?
Click to expand...


Planojc said:
On mine the pump gets it's power from the ignition switch, then to a toggle switch to turn on the pump. With the ignition switch off the pump will not stay on, in case you forget to turn off the toggle switch.
Click to expand...

It is a normal toggle switch so that when I have to turn it on while driving I don't have to try to lean down and hold it on and steer the car at the same time. I don't think it's a big deal to accidently leave it on as long as it's a low pressure pump. It can work intermittently or continuously. I, likewise, get the power to the switch through the ignition switch so it won't run with the key turned off. I don't have any kind of safety mechanism to turn it off in a collision because I don't ever have it on long enough to worry about that.
 
I was using an electric f. p. exclusively up until recently. Now I have a rebuilt mechanical pump from kenct and use the electric one only as a back up. So far I haven't had to use the electric one once since I installed Ken's. It works great! And, yes the electric pump will push the gas through the mechanical one. Good luck.
 
Forgot to mention; I use the toggle switch meant for the dash light, (just left of steering column on the 34). So I can turn it off or on at will.
 
I fitted a Toggle Switch and cover part number TG-220 from Ron Francis Wiring for my electric fuel pump on my V8, the spring loaded red cover will actually help to switch the toggle switch of if anything untoward happens. It works very well and gives one a certain amount of safety.
 
"It works very well and gives one a certain amount of safety. "

Very little if you have to switch it manually.
 
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You are right. In V8 Times magazine there was a write up by Aaron Dick, he recommends using a switch that powers the fuel pump on a 2.5L Ford industrial engine which contains two switches one that is normally open (10 amp rating, closes at 7.5 PSI which is a higher rating than a normal oil pressure switch which actuates a light) and one that closed (0.5 Amp rating, opens at 6 PSI). The pump is powered through the normally open switch, and the normally closed switch can be used to power a low oil pressure warning light.
I do have a spare one of these switches.
 
Pete, will those inertia switches work on 6 volts if so it would be logical to wire one on the wiring to the electric pump which would be fitted close to the gas tank.
 
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