Electric Fuel Pump

[PECO]

The following questions relate to a '70 Challenger R/T with a 383 and AFB carb. I'll give you some background info first. I live in Alberta, so we have pretty harsh winters where classic cars do not venture outdoors for months at a time and over the summer the car may only see the street on a weekend. My problem is that with the car sitting for extended periods it is very difficult to start as the mechanical fuel pump has to bring fuel up from the tank. I hate cranking the engine for extended periods and draining the battery before it will start. What I'm thinking of doing is installing a switchable electric fuel pump to bring up the fuel to mech. pump only. I assume that the mech. pump is not flow thru'. The mech. pump works well and would be the operating pump once the engine fires. The electric pump would need to be self priming and flow thru'. Any comments and/or better ideas and pump recommendations would be appreciated

 

[Steve340]

Take the air cleaner off and prefill the carb with fresh fuel out of a small plastic squirt bottle.

 

[heminut]

Take the air cleaner off and prefill the carb with fresh fuel out of a small plastic squirt bottle.

Exactly what I was going to recommend! And BTW, electric fuel pumps are noisy!

 

[moparleo]

Now "pre filling" does not mean down the throat. Fill the fuel bowls through the vent tube and use the accelerator pump to prime the carb. Less chance of flooding and fires...

 

[70chall440]

I went down this route some years ago with my 70 Challenger 440 6 pack. It will work but you have to ensure that you get a pass through electric pump (think Holley red pumps) if you intend to shut it off after you get the system primed.

Yes they are/can be noisy, however you can mitigate this by putting some rubber between the pump and whatever you mount it to. If you do go this route, make sure to use a relay to activate the pump.

Ultimately I removed the pump from my car because I went to an EFI 6 pack system and now have an in-tank pump.

 

[Iguana]

Not sure about use with mechanical pump, but as far as noise, I went through two different external electric fuel pumps before finally switching to a Holley in-tank unit made for e-bodies. Both externals were so loud it took all the fun out of driving my car.

 

[MoparCarGuy]

Many people plumb an electric fuel pump in series with the factory mechanical pump but this can be disastrous if the mechanical pump's diaphragm fails. The electric pump can then fill the oil pan with gasoline. One measure to help prevent this is to wire the electric fuel pump so that it only runs in the Start key position and, after starting, only when there is oil pressure. That lessens the chance of the pump running continuously after a mechanical fuel pump diaphragm failure.

Simple option: Prime the carb bowls as others have said.
Option 2: Install an electric fuel pump at the rear by the gas tank (bypassing your mechanical fuel pump) and a regulator in the engine compartment with a gauge.
Option 3: Go EFI with a new EFI-ready in-the-tank electric fuel pump and have your car start in just a few seconds. Holley Terminator X Stealth is highly recommended!

 

[70chall440]

I concur with wiring any electric fuel pump so that it only runs when the ignition is on via a relay.

 

[moparleo]

Another safety idea for electric fuel pump use is to wire it through the oil pressure sensor switch ( gauge type) This will shut it off if the oil pressure drops to 8 lbs.

 

[PECO]

Thanks for your thoughts and ideas. I'm thinking that filling the bowls might be the easiest and most practical way to go, as it would be only after the car has been sitting for an extended period of time.

 

[70chall440]

Well you can also go and start it periodically and let it run, if you do let it get to operating temp before shutting it down.

 

[Steve340]

The modern blends of fuel seem to vapour off more easily than the old fuel.
I have to fill the float bowls on my 440 motor if it sits for a few weeks. It will start I just don't like grinding on the starter motor.

 

[kudakoda]

Many people plumb an electric fuel pump in series with the factory mechanical pump but this can be disastrous if the mechanical pump's diaphragm fails. The electric pump can then fill the oil pan with gasoline. One measure to help prevent this is to wire the electric fuel pump so that it only runs in the Start key position and, after starting, only when there is oil pressure. That lessens the chance of the pump running continuously after a mechanical fuel pump diaphragm failure.

Simple option: Prime the carb bowls as others have said.
Option 2: Install an electric fuel pump at the rear by the gas tank (bypassing your mechanical fuel pump) and a regulator in the engine compartment with a gauge.
Option 3: Go EFI with a new EFI-ready in-the-tank electric fuel pump and have your car start in just a few seconds. Holley Terminator X Stealth is highly recommended!

I vote option 3 as I also live in Alberta and just replaced my mechanical pump and carb with the Holley EFI system on my 70 cuda and it left me wondering why I didn't do it years ago