Carter Electric fuel pump Question

[bogster]

Hi All,

I've got a question regarding electric fuel pumps. Once wired in the pump should switch on when the key on the ignition is moved into the second position just prior to cranking the engine over. My question is if you leave the ignition in that position but do not crank the engine over what stops the fuel pump from overloading the carb with fuel? Probably a daft question but it is bothering me. I have nightmares of pumping fuel all over my engine with the key in this position prior to starting.

Could someone explain what happens?

Thanks

[wilf]

Bogster - there is a needle valve inside your carb, operated by the float, which stops the flow of fuel once the correct level has been reached.

What you might consider, is to wire your fuel pump through an oil pressure switch, so that in the event of an accident (where the engine stops), so does the fuel pump.

You could also consider the use of an inertia switch out of a production car to do this as well.

[David Large]

The float in the carburettor rises with the fuel level in the carb and closes the fuel inlet (just like the cistern in your wc). When the pump gets the pressure resistance, it stops pumping (just like the water pressure is held in the supply pipe to your WC).

Cheers

[chedz]

I have a carter, so far I've never heard it stop when the key is in pos 2 without the engine running, it just wurrs away non stop. Does it take quite a while for the pressure to stop the pump or do some pumps not have this cut out feature?

ty
Graham

[wilf]

Pump never stops, it just runs in a "stalled" condition.

As std, a Carter pump is internally regulated to 5-6 psi, which is about right for a Holley/Edlebrock (although too much for SUs, which like about 3 psi).

[bogster]

Thats grand lads,

Thanks for the ino.

:thumb:

[crendonman]

Originally Posted by David Large

The float in the carburettor rises with the fuel level in the carb and closes the fuel inlet (just like the cistern in your wc). When the pump gets the pressure resistance, it stops pumping (just like the water pressure is held in the supply pipe to your WC).

Cheers

The only difference is that my cistern uses a lot less water, than my car does fuel!! :thumb: :boohoo:

[Purple AK]

Originally Posted by crendonman

The only difference is that my cistern uses a lot less water, than my car does fuel!! :thumb: :boohoo:

Time for a brick in the tank then Dave. (Or under the pedal)

[skorpion]

I have also a Carter (18 psi) and it is for sale. It makes more noise as my 393w stroker with sidepipes!
The carter has an internal recirculation and when it has to fight up to a regulator, it is really noisy.
I use a pressure regulator but seams the thing can't handle it...
The engine runs but when driving at constant rpm, the fuel delivery seams to come in pulses ? I think...perhaps other causes possible for the not constant power output at constant low rpm's ?

i am now planning to buy a less powerfull pump from carter because I want to keep my bracket and feedlines setup (i am lazy)...this one has 8 psi and perhaps my regulator can handle it better. If not, i am going to remove the pressure regulator and connect it straight to the carb. The edelbrock carb wants 5.5 to 6 psi...I guess 8 psi will not harm ?

note: i have no return line.

Regards,
Andy

[Mr Bling]

The other option is to fit an isolator switch in the circuit, dash mounted or under dash - for those occasions when you need the ignition on when the engine is off for diagnotics etc - also acts as anti theft device.
J4NCOB:thumb: