Favour to ask

The fuel pumps I used for banger racing (one of a selection of 60s era SU
pumps depending on car being raced) all cut out when the floats shut and
started again when the back pressure dropped.

Those who had Morris Minors as road cars will be well aware of the
constant ticking as they started to run out of fuel. Jags and Minis had
them in the boot so you didn't get the warning sign as the pumps started
sucking air as you cornered.

 

I think the OP has just got the pump without any of the other gubbins
and he didn't know if there was a pressure release valve somewhere later
in the system designed to let the petrol back to the tank when a certain
pressure was reached.

 

I bought a used Facet pump from a bloke in the pits. That went onto
every car I raced, then moved to just about every car I used in
competition, just because it was so reliable, easy to mount at either
end of the car (it didn't GAF whether asked to push or pull) and was
capable of pumping vast quantities of fuel. It provided for all sorts
of carbs, from little SUs to the mighty 45DCOEs. It lives in a box
now, semi-retired.

Well, the Moggy pump was a puller, mounted on the bulkhead. It amused
me to hear it ticking when idling at the lights, doing half a
teaspoonful of fuel with each tick. You're right about the running
out though - the rattling came through loud and clear.

My old 4.2 Jag had a hole in one tank and a dodgy pump on the other,
wehn I got it. Once I'd sussed that (it wasn't obvious that petrol
was leaking, with the rate that old bus went through it on its own)
and swapped the good pump onto the good tank, life became altogether
easier, if a little less exciting.

The back roads out of Ilfracombe and Lynmouth became much less of a
touch-and-go affair, for example. The gradient must have put the old
pump under stress, trying to pump sufficient fuel up a 1:3, so the
engine would just stop with no warning at all, as the huge SUs
simultaneously spat their last dribble. On a steep uphill, with a
sheer cliff face on one side and a little stone wall on the other,
"protecting" vehicles from a hundred-odd feet drop, there was precious
little time or momentum available to pick a spot and haul the beast in
for a dead stick landing.

A ton-and-a-good bit of Jag, sans power steering and brakes, was a bit
of a lump to wrestle to the side of the road and stop before the
screaming started. The swearing was already in full flow, of course,
and continued through the leaping from the cockpit, opening the boot,
seizing the handily-placed Jagaur-monogrammed screwdriver (special
tool B.A.S.TARD), smacking the bloody pump one in the approved manner
and the reversing the whole process in the proper Haynes style.

I miss that car sometimes, when I forget about its little foibles.