Safety Switch On Petrol Pumps.

When connecting the wiring to the fuel pumps on my G.T.D,I noticed on the loom diagram that the pumps were just connected to switches on the dash via the ignition.It got me a bit worried ,as this means if the car was involved in a collision and the engine stalled,the pumps would still be pushing petrol through them.At looking back at the instructions for the pumps(Facet Pumps)it was quoted that by connecting the wires from the pumps though the oil pressure switch,this would act as a safety cut out if the engine stalled in a accident,reducing the possibility of carb flooding and a fire.Has anyone tested this system,and has it caused any probplems ?.
 

Ron Earp

Admin
A better route, if the car is not a track only car, is to use an inertia cut out switch. These are only practically every modern car on the road and will cut the fuel pump in a collision. HAving an accident doesn't mean the motor cuts off, but it definitely will trip these switches. Cheap too, get them from bone yards for nothing.
 
Brian, on most race cars this is SOP. The only problem you may encounter is after a long storage period your fuel system is dry and won't have enough fuel to start the car. You will have to build up oil pressure before the pumps will run. Not really a bad thing as having oil pressure before you start is a good. I love the guys who start their cars and right off have to hit redline. Most of the switches have a very low pressure setting, 3 or 4 PSI, so getting enough pressure is not difficult.
Bill
 
Brian,

I recently added an inertia switch to my fuel system.
Best $24.50(new, including milspec plug) I ever spent!
That's cheap fire insurance!

Bill
 

Trevor Booth

Lifetime Supporter
Supporter
I use a momentary switch ( like a starter press button) to prime pumps. Once engine starts oil pressure switch takes over to supply power. Inertia switches in road cars are not common down under.
 

Trevor Booth

Lifetime Supporter
Supporter
Bill,
Where can I purchase Inertia switches, do you have brand and part number please. These are a better option than oil pressure sw method.
 
Trevor,

I ordered mine through my local auto parts shop. It was built by First Inertia Switch (PN: 040220A XF32-9341-AA)
It's about 1 1/2"W x 2"H x 1"D, and has a red reset button on top. Very simple to install. $24.50USD, including milspec, waterproof plug(plug was a separate part #).
I hope never to find out how well it works!

Bill
 

Lynn Larsen

Lynn Larsen
Trevor,

The one Bill has is the same one I installed. This is a great insurance policy! The idea of a momentary switch to bypass the oil pressure cut-off is a neat idea as well.

A hidden switch on the ground side of the intertia switch relay is not a bad security device also.

Lynn
 

Malcolm

Supporter
On my GTD I have the First Inertia fuel cut off switch. It triggers at 10g which is easy to get in an accident. The power for both pumps goes through this switch and it is concealed behind the dash bolted to the chassis firmly. First Inertia used to be based 10 miles down the road to me and my friend Neil used to be their calibration engineer.

I have only ever triggered it once and that was during a spin off at Bovington Sprint where I did a bit of cross country!

It would definately do what you are looking for, conscious or unconscious!
 

Trevor Booth

Lifetime Supporter
Supporter
Thanks Bill,
I shall arrange for a friend of mine in LA to get me a couple or three.

Lynn,
On my road car I have a hidden fuel switch that operates a latching relay with a 10 sec delay. The fuel gauge sender is also wired thru the relay. The theory is that the would be thief can start the car and drive away but will only get as far as 10 secs will allow and the fuel gauge would read Zero. Has not been "put into use" by a would be, but you never know.
Trevor
 

Peter Delaney

GT40s Supporter
Trevor - thanks mate. Not surprisingly, I am used to things being expensive when it comes to this car - the set of hub/bearing assemblies set a new record at over AU$2,000 !!!

Still, I think it is worthwhile having the inertia switch - the only advantage I can see in not having one would be the fact I could stop paying my life insurance premiums !!

Kind Regards,

Peter D.
 

Trevor Booth

Lifetime Supporter
Supporter
I will discount it to cost, just for you. The 2000 dollar affair, you have seen my play room, you only had to ask. Next time.....
 

Denis Bedford

Denis Bedford
Peter and Trevor these switches are fitted to all jaguar xj6 and more contact Graham Garson at British Cat Components or as I call him Pommy Pussy Parts 073274 1966
"He'll save ya"
 

Peter Delaney

GT40s Supporter
Trevor - thanks old son, much appreciated - that should bring it in just under the $2k mark !! If I had known then about the play-room & the quality of the suspension parts you have made up for the clubman, etc, I would have called you & asked you to make up a set of hubs/bearings & a whole bunch of other bits ! Next time ? As far as this lot is concerned, there better not be a bloody next time !!

Denis - thanks for the tip, I'll give Graham a call tomorrow & let Trevor know the story.

Kind Regards,

Peter D.
 

Malcolm

Supporter
Peter and Trevor these switches are fitted to all jaguar xj6 and more contact Graham Garson at British Cat Components or as I call him Pommy Pussy Parts 073274 1966
"He'll save ya"

My recollection also confirms this that the first intertia switches were used on Jaguars. If you can't find a new one try a scrap yard!
 

Pete McCluskey.

Lifetime Supporter
Peter, I think you have the same setup as me. And I am pretty sure that the Autronic computer cuts fuel supply when the engine quits.
 
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