[TR] Fuel pump safety switch

[Randall]

> I have installed Webers on my project TR3, which necessitated an electric
> fuel pump,

Hmm, I was under the impression that Webers would work with the stock fuel
pump.

> I know there are
> safety switches which tie into the oil pressure and ensure pump cut-out in
> the event of catastrophic failure.
> 
> Does anyone on the list have experience with these?

Not as a pump cutout, but the standard 3-terminal oil pressure switch from a
later TR6 (and many other cars) seems to be a fairly reliable device and
would work as a pump cutout (using the contacts intended for the anti-runon
valve).

I believe the threads are standard 1/8" NPT, and it should be easy enough to
drill and tap a suitable hole in the filter head for the switch.

If you add an override pushbutton in the cockpit (for building fuel pressure
before starting), it would also give you a "limp home" mode if the oil
switch fails.

I think I mentioned before, Bosch made a special relay that monitored the
points and only enabled the pump while the engine was turning.  Some have
said they were unreliable, but IMO that was mostly due to being mounted in
damp locations.  The VW Rabbit I was given appeared to still have it's
original relay, and it still worked fine when my stepson eventually sold the
car some 10 years later.  Found on all cars with Bosch fuel injection and
points, I believe.
http://tinyurl.com/7g8msv

Randall