Electric Fuel Pump and mechanical

Hayzoos

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I have been researching electric fuel pumps and found a nice plastic housing one 5-9 psi 30 gph which should fit nicely behind the rear axle at the bottom of the tank. Plumbing it should be simple since I have all new lines. To put it simply the fuel system is all new except the filler tube, I rebuilt the carb. I kept the line to the carb and the hidden rigid section in the front frame rail, which I sprayed carb cleaner trough to clean them.

In my research I see the mechanical pump left in place, some saying to regulate pressure. I don't see it regulating so much, but those saying it regulates say you need a regulator if you delete it. Does anyone have first hand experience with keeping the mechanical in place with an electric? I know one of the drawbacks pointed out is a failed diaphragm would result in gas in the oil.

I was also thinking of setting up a multiple relay circuit to pump only when the key goes from off to on, then kill the pump when key at start and keep the pump de-energized on key return to on. Or setup a short timer when key goes from off to on. The point is to just top off the carb bowl before starting. Thoughts?

To allow remote start, I also thought about adding a pull solenoid on a sliding linkage to the throttle to set the choke and squirt the starting fuel charge.
 

Duke5A

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It was an option for at least late model fleet vehicles to have an electric assist pump to combat vapor lock. I wouldn't use both though. Just get a Mr. Gasket pump or something with a regulator and use that. Fuel pump needs to be wired through a relay and be energized with a circuit that sees power at key-on and crank.

Shop around and read reviews too. Lots of these aftermarket electrics are noisy as hell.
 

Hayzoos

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Thanks for the reply. I am familiar with a standard electric fuel pump installation. Don't forget you want to kill the pump in the event of an accident. A popular solution for electric conversion is an oil pressure switch. A common factory electric pump fail safe is an inertia switch.

I have first hand experience in the noisy pumps. I replaced a failed in tank pump in a 93 Grand Cherokee with an external. Granted it was a higher pressure FI application, but noisy as hell as you say. On that vehicle, it just added to the harmony of glass pack and big mud tires, a real rolling symphony.

BTW, I love your animated sig graphic.
 

Mikes5thAve

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If all you want from the relays is to run the pump before starting to prime the carb why not setup the electric pump with a push button just to prime and call it done.
 

Hayzoos

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I could just use a push button. But I have a remote starter I want to install on it. If I use a latching relay which delatches on starter signal, then the remote starter could be added. I would first have to automate choke set and start fuel charge for remote start to work. Trying to design a solution which if it fails, does not leave me dead in the water. I should be able to fall back on how it works now.
 

Duke5A

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I could just use a push button. But I have a remote starter I want to install on it. If I use a latching relay which delatches on starter signal, then the remote starter could be added. I would first have to automate choke set and start fuel charge for remote start to work. Trying to design a solution which if it fails, does not leave me dead in the water. I should be able to fall back on how it works now.

At this point you should just fuel inject it. Holley Sniper kits make it pretty damn easy.
 

Hayzoos

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Holley Sniper is not in the budget right now. This car was a barn find, stored for 23 years. I put in new fuel, return, vapor lines, gas tank and sending unit, gas cap, pump, filter, and I fully cleaned and rebuilt the carb. I considered FI at that point but the time/money wasn't in the budget. If I pull that trigger, being the DIY type, I would do something like a megasquirt and a 2bbl throttle body injection. A multipoint injection would not be out of the question though if I would have to change the intake manifold.
 
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