Andy,
1)I'd keep it in the toolbox and install it if/when necessary.
2)Under the car it's subject to dirt and water, and there is one more
wire involved.
3)Mounted a la MkII but not MkII plumbing will look strange
4)Mounted a la MkII with MkII plumbing puts two more fuel lines over
the exhaust manifold and another two connection joints in the middle.
Since my TD is a MkII, I'm safe (I hope) from simultaneous pump
failure. Each time a pump has stopped working, it's been from age (first
stopped at about 15 years), or from lack of use. I carry a spare pump to
lend to those in need. Swapping the pump takes five minutes or less--two
fuel connections, one electrical connection, two machine screws in the
back.
Running fuel lines over the manifold is not, in my opinion, the best
positioning for them. Two more lines will add to the potential for
mischief. Moss teflon lines are guaranteed for life. The OEM type rubber
lines with wire braid over would perish with annoying regularity. One
hot day, when stopped at a signal light, the fellow alongside called over
to me and asked if I knew the paint on the bonnet was bubbling. Yep,
fuel line spraying right onto the manifold. Aside from needing to paint
one panel, no harm was done.
One supposes that SU carbs are designed to work with 2.5 psi pressure,
and the pumps designed to deliver that, in order to minimise the pressure
in notoriously failure prone flex fuel lines. (That may be cart before
horse reasoning)
Bob
On Thu, 11 May 2000 21:16:22 -0400 (EDT) Andrew Moyce <amoyce@pol.net>
writes:
> I've just gotten a rebuildable SU fuel pump through EBay and plan to
> use it as a backup for my TD. I have read earlier threads on the
> subject, and think I have four options.
>
> 1) Club wisdom (FWIW) is to carry an extra fuel pump in the toolbox.
>
> Obvious drawback of trying to mount and plumb it on the road.
>
> 2) Since others have found that fuel will freely pass through a
> non-energized SU, I could mount it in-line under the car in front
> of
> the fuel tank with a switch to turn on when needed.
>
> 3) It could be mounted on the bulkhead and outboard of the original
> fuel pump a la TD mark II. It could be plumbed in line with the
> principal fuel pump and energised with an A-B switch.
>
> 4) It could be mounted and plumbed exactly as in a Mark II, with
> both
> pumps running all the time, and the assumption that one could take
> over if the other failed.
>
> I have transistorized my main fuel pump, and wasn't planning on
> doing
> same to the backup pump
>
> Comments, suggestions, potential problems?
>
> Andy Moyce
> 52 TD
>
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