Electric Fuel Pump Hook Up

[Jeff Baker]

I am going to install an electric fuel pump in my 42 Cadillac. I was wondering where you attached the wire for power? Did you run the pump off a seperate switch? The pump is an Airtex E8011. 

[Don Boshara #594]

On my '40 I use the electric pump for starting after a long non-use period and whenever it starts to vapor lock. I installed a toggle switch under the dash wired to the accessory side of the ignition switch. The pump is a 6 v. rotary from NAPA in the fuel line in front of the gas tank with a filter before the pump. It doesn't interfere with the mechanical pump (at least up to 80 mph) and I have found no need for a bypass or check valve.

[T J H]

A warning / recomandation:

You should think about using some sort of safety switch that will shut down the fuel pump if the engine stalls.  I have seen and heard of a few cars with fires due to electric fuel pumps.  The one I saw the results of was a guy that lived down the block from me.  I think his car was a 40's Lincoln (it was hard to tell in the rubble).  He HAD a nice house with a attached garage.  I guess he pulled in the garage and left the car running (with the door open) and ran in the house for a second which for what ever reason turned into several minutes.   For some reason the engine stalled.  The electic fuel pump kept running and there was enough pressure to over come the needle & seat (or perhaps something was stuck in them and thats why it stalled in the first place) and it filled the manifold with fuel to the point it began to spill onto something hot or caught a spark from something and ignited.  The fire on its own was bad enough but it had the fuel pump still running and pumping fuel onto the fire.   The car and house were both a total loss.  They tore the house down and built a new one.  I dont know what ever happend to the car but between the fire and all the debris it didnt look very good.  THe fire started in the house because of the burning fuel running down the stairs and catching the carpet on fire which then spread to furniture and other stuff.  The man and his pets got out without injury.

You can easily make a circiut to cut out the fuel pump.  GM used a oil pressure switch.   Most of the mid 70's and 80's carbed cars used this system.  The oil pressure switch is open without pressure and closes with about 4psi of pressure.  They also used this switch to run the electric choke, thats why you used to see the oil/choke light on the dash.  You just need to run the power for the pump or power for the relay if you have a high draw pump through the pressure switch.   Most of the time starting is not a problem because there is enough fuel in the bowl to get the engine running and therefore oil pressure and electric pump.  I have seen people that have put in a primer button to run the pump for a few seconds before starting and when they have vapor lock problems.  I have never looked that close but I think that Holley and other popular aftermarket fuel people make a kit that I would assume include some sort of pressure or tach switch to do the same thing.

The other fires I have seen have just been a big bummer and burnt some wires and messed up the paint on the hood. 

Do your research and do what works best for you and your car.

TJ H
20664
StPaul/Mpls MN USA