And there's at least one other type - one that I'm personally
using on my own 69 TR6 PI - one thing you definitely don't want
with the PI version is the fuel pump continuing to run when
you have an accident. Those little babies sure can create a
small geyser if you leave one end disconnected...
Anyway, I digress, the cutoff switch I have installed is
installed as a routine when cars are fitted with LPG (Liquid
Petroleum Gas - not sure what you call it in the States)
over here in Oz. The idea with those systems is that the
solenoid which lets in the gas shuts off when the engine's
not running so you don't get an explosion. Basically the
switch gets an input from the ignition coil (or electronic
tacho input) and kills the electricity to the pump if the
engine stalls (at least that's what it does with the TR6).
To reset it you turn off the ignition and turn it back on
again. It gives you (I think) one and a half seconds of
running time if you flick the ignition switch on, but
don't start the car, so the fuel has enough time to get
up to pressure before you start the engine. It works very
well, and you don't have to go to the bother of opening
the bonnet (hood) to reset it in case of an inadvertent
tripping of the cutoff...
The only problem is that I can't remember exactly what
they're called - they're generic to all makes of car
and just hook up to the fuel pump relay input. I think
they're just called LPG safety switches over here, but as
I said, I'm not sure... Cost was about AUS$10, so they're
cheap too.... Oh, and it's about the same size as a
small automotive relay, and has a similar case, so it
fits just about anywhere...
Frank Biedermann
1969 TR6 PI
Adelaide
AUSTRALIA
> The Ford switches come in two shapes, but I'm not sure if
> there are car
> specific trip weights. One type of switch has a rectangular
> white reset
> button and the other has a red round button. The switches
> wire directly
> inline with the fuel pump power feed.
>
> Another fuel pump safety system is to use a oil pressure
> switch from a fuel
> injected mid 80's GM car or a GM that has a electric choke.
> These have
> usually have three push on connections. The paralell ones
> turn on when the
> pressure is above ~ 10 PSI, the center one grounds on when
> the pressure is
> below ~ 4 PSI. The fuel pump power can be wired directly as
> the paralell.
>
> A down side to using a GM switch is that it requires a
> seperate circuit to
> run the fuel pump when the engine is cranking and hasn't
> built oil pressure.
> The circuit would be the same as a ignition ballast bypass in
> a point dist.
>
>
> Harold
>
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