Inertia Switch

[doug2008]

Ok how do I check fuel inertia switch , can I pull wires off temp to test fuel pumps not sticking cheers

[73stagman]

yep. And if you connect them you will just bypass the inertia switch..... many people have done that permanently against much advice from fellow forumites

[Motorsport Micky]

yep. And if you connect them you will just bypass the inertia switch..... many people have done that permanently against much advice from fellow forumites

Hmmmmmm hanging upside down from the seat belts after a survivable accident and listening to the fuel pump diligently "ticking" as it tries to continue pumping fuel up to the engine which isn't running and an ignition that can't be turned off...just enough time to wonder what your children are going to do without their parents and then...Wwwhhhuummpppff...No thanks.

Micky

[73stagman]

Hmmmmmm hanging upside down from the seat belts after a survivable accident and listening to the fuel pump diligently "ticking" as it tries to continue pumping fuel up to the engine which isn't running and an ignition that can't be turned off...just enough time to wonder what your children are going to do without their parents and then...Wwwhhhuummpppff...No thanks.

Micky

I agree with you absolutely! I had a long argument on here about bypassing the switch a while ago and others were of the opinion it doesnt matter!
I absolutely agree with you that it does matter very very much!

[jakesmig]

I had exactly that argument with the other mechanics when we were preparing our rally cars, I argued removing them, they argued against and won the day.
The inertia switch is placed up behind where the glove box would have been on these cars and generally inaccessible. One of the cars broke down in the 1st forest stage of the Speyside Rally having gone airborne over a classic jump and had come down fairly hard. They pulled into the side an parked up, rally over, gutted, total waste of £2000.00.
We went in after the stage was closed to tow them out, and the driver & navigator were searching all over the car for the fault, and everyone was more than a little miffed when I reached under the dash, pressed the button on the IS and the car started first time.
Needless to say the switch was removed before the next event.

[73stagman]

I had exactly that argument with the other mechanics when we were preparing our rally cars, I argued removing them, they argued against and won the day.
The inertia switch is placed up behind where the glove box would have been on these cars and generally inaccessible. One of the cars broke down in the 1st forest stage of the Speyside Rally having gone airborne over a classic jump and had come down fairly hard. They pulled into the side an parked up, rally over, gutted, total waste of £2000.00.
We went in after the stage was closed to tow them out, and the driver & navigator were searching all over the car for the fault, and everyone was more than a little miffed when I reached under the dash, pressed the button on the IS and the car started first time.
Needless to say the switch was removed before the next event.

Frustrating I'm sure but not half as frustrating as rolling on to one side with the fuel pump pumping pure fuel onto an electrical fire.... and.....unconscious driver
I would rather be a poorly informed non finishing rally driver than a fully knowing burnt father not getting home to his kids

[KOY 23]

I had exactly that argument with the other mechanics when we were preparing our rally cars, I argued removing them, they argued against and won the day.
The inertia switch is placed up behind where the glove box would have been on these cars and generally inaccessible. One of the cars broke down in the 1st forest stage of the Speyside Rally having gone airborne over a classic jump and had come down fairly hard. They pulled into the side an parked up, rally over, gutted, total waste of £2000.00.
We went in after the stage was closed to tow them out, and the driver & navigator were searching all over the car for the fault, and everyone was more than a little miffed when I reached under the dash, pressed the button on the IS and the car started first time.
Needless to say the switch was removed before the next event.

Strange logic, why not move the switch so it is reachable by the driver??

[jasper]

Iv never had the inertia switch in my car , the PO must have removed it
Are you saying this is a bad idea not to have one ?
what do they do , why are they there ? and why dose my daily drive not have one ?
sorry for all the questions
John

[73stagman]

Iv never had the inertia switch in my car , the PO must have removed it
Are you saying this is a bad idea not to have one ?
what do they do , why are they there ? and why dose my daily drive not have one ?
sorry for all the questions
John

With an electric fuel pump the inerrtia switch disconnects the fuel feed in case of an accident. Stops the pump emptying the fuel tank if the fuel line gets damaged which almost certainly means there will be wire loom damage aswell leading to possible shorting and sparking..... fuel fire bang

Your modern daily fuel injected car will have similar system all linked into airbag and other impact safety systems

[jakesmig]

Strange logic, why not move the switch so it is reachable by the driver??

Drivers got enough to do, besides if the engine died because of the IS closing down the driver, or navigator would likely be tempted to hit the switch whilst the engine was 'dead'
but the ignition still on and gears engaged, hoping that the momentum would 'bump start' the engine. The most likely affect of this would be an electrical spike going through the ECU which could fry the unit.

Have to say that in all the years I've been involved with the SRC Rally i cannot recall any car bursting into flames, i daresay there have been some, just that i can't remember any.

Interestingly, back in the 90's the insurance industry investigated the incidences of fires in cars involved in collisions and determined that the majority of fires were caused by brake fluid splashing onto the exhaust manifold because the fluid resevoirs were becoming detached.

john

[Staggard]

So boys I have a question, if the inertia switch is so important to safety, why ( to my recollection) was not all vehicle fitted with an electric pump also fitted with a switch. 1100's, minis, A60's ,Westminster's, moggie 1000's the list goes on.

[73stagman]

Same reason as they werent all fitted with seat belts and hazard flashers as standard probably. Triumph cars were always pushing vehicle development. Loads of "firsts" which have become standard fit.

[Staggard]

Same reason as they werent all fitted with seat belts and hazard flashers as standard probably. Triumph cars were always pushing vehicle development. Loads of "firsts" which have become standard fit.

What first's were they then ??

[1959terry]

First to have a heated rear screen on the hardtop to keep your hands warm when you was pushing it

[Staggard]

First to leave sand in the blocks for those that could not afford a beach holiday