9 replies to this topic

[noeman]

Hi all,

Is there a way fit a inertia automatic safety switch ti a electric facet fuel pump?
This as a safety measure incase of an accident.
If so, what switch could be used?
Many thanks

[nicklouse]

Sure just wire it into either wire on the pump.

 

the power feed is preferable.

[danc]

Very simple to do, I used a Ford one. If you're buying something used, be sure to get a bit of wire pigtail on the mating connector.

Mine is in the engine bay but I can't see location being a problem as long as it is oriented correctly.

[Cooperman]

An inertia switch will only stop fuel supply, it won't stop the engine immediately.
In fact, a petrol fire is most unusual in a crash. The biggest cause of fire is hydraulic fluid spraying onto the exhaust manifold or even on hot brake discs.
It is best to fit an inertia switch on the main ignition feed which kills power to the ignition, fuel pump (if electric) and other power circuits.

[Earwax]

Hi Noeman

 

This may be useful - but i am sharing it more for confirmation .....so not absolutely sure.

 

If you look up Tachometric relay    - for Bosch  or for Fuel Relay  these might be the same sorts of inertia switches you refer to?.  I think one sort get their data off the pulse feed at coil ( or lack of if engine stops) and another sort work off oil pressure info ( again or lack of) -  

 

Are these the same as inertia switches ?  I have a vague recollection of dialogue about how big bumps can sometimes activate them ( reset required to continue)  How do rally cars cope Cooperman?? 

Hoping someone could chime in and help my understanding as well.

 

Cheers Darryl

[Steam]

As I subscribe to the KISS principle I have switches on the dash. 1 for the pump and 1 to kill the ignition.

Also work well as security as they are not marked.

[nicklouse]

As I subscribe to the KISS principle I have switches on the dash. 1 for the pump and 1 to kill the ignition.

Also work well as security as they are not marked.

The problem with that is they don’t work if you are unconscious.

[johnR]

You can't have too much fuel safety - I keep meaning to fit a collision cut-off switch to augment my manual switch - with the mini being so small and fragile they're never going to come off well in accidents!

[IronmanG]

I just received some wiring bits from David of wired by wilson fame including a pump inertia switch.
I do wonder how often they go off due to banging and crashing in a mini

[Cooperman]

It's ironic that on race and rally cars it is not feasible to fit an inertia cut-off switch as they would deploy under competitive driving conditions.

In fact, when I prepared my Rover 214Si for Endurance Rallies I had to 'de-wire' the inertia switch. I was refuelling on a long rally when a Peugeot 106 was towed in with a 'failed engine'. I walked over and the driver said that the engine had cut out on a bumpy road and it would not re-start. He had retired from the event. I asked him to open the bonnet, leaned in and re-set the intertia switch. It started straight away. He sure was peed-of and went away to remove the inertia switch from the car.

Of course, it is different with a road car.