Interrupter pump - how do they work?

[Jono]

Hi,
Just wondered if someone could explain how an interrupter fuel pump works?
I have a Facet pump.

I've had all the wiring out of the GT Corty, to try and sort out some issues. Now it is back in, as soon as I flick the pump switch it kicks in.

Previously I think it only kicked in when I also turned on the ignition, so not sure if I've bodged a connection somewhere?

 

[Randy V]

Most of them have a low pressure regulator built into them. When the pressure hits a specific threshold, the circuit to the pump is interrupted. If you are out of fuel or low on fuel - your pump should continue to run as long as power is applied.

 

[Jac Mac]

Sounds like you have wired it to a live source or the live side of the key- best you change that so it only works when the key is on, dont want to end up in ditch or trapped in the car with fuel being pumped everywhere because you cannot reach the switch.

 

[Doug Clark]

My old Yamaha FZR1000 bike had one of these after a period of time the pump would stop regardless of whether there was pressure or not(10 seconds roughly), which thinking about it now would be a good safety feature for the use of such a pump on a car

 

[Ian Anderson]

Jono

To me it sounds like you have connected the feed that goes to your Pump Switch to the permanently live side of the key switch

Move it to the other side of the key switch

In effect Battery - key switch - fuel pump switch
That way if either your switches is turned off the pump will not run

Ian

 

[Bill Musarra]

If you want to add some real safety, add a low pressure cutout switch like the one below. Most of the speed shops have them. It essentially cuts power to the fuel pump or ECU(your choice) when a preset pressure is met. They are anywhere from about 7 psi to 12. The third lead can go to a low pressure light for warning. This could be added in series to an inertia switch. A bypass button can be added to do just that for cranking. It also add a safety feature, in that if someone doesn't know about it, they can't crank it. Read steal it.

Bill

 

[Jono]

Thanks. Got an auto sparky coming round on Wednesday to sort out some other gremlins, i'll get him to check / fix!