I have a '69 MGB Roadster project car that I am slowly restoring. The
fuel pump makes an awful racket (tappity-tappity-tappity) constantly
and I would like it to stop. The car runs nicely and there doesn't
seem to be a problem with fuel delivery. From what I have gathered,
should tap a little when the ignition is initially turned on but
should then stop. I have seen postings that mention the "reassuring
tap" of the fuel pump. Does this refer to the initial power-up or is
my constant tapping normal and if so how do I make it stop?
Expect to hear a rapid ticking noise from an SU when first you switch on.
This should slow and stop before you turn the key, as pressure builds
rapidly up in the fuel hoses further forward. The pump is set up primarily
as a 'pusher', that is why it is mounted so low.
Generally you do not hear the periodic click when the engine is running.
If the pump is clacking away on turning the key,and does not slow & stop
then either you have a large ( and dangerous) puddle beneath the carbs, or
perhaps the pump diaphram is split. In this case you may barely be reaching
operating pressure at the carbs.
Do you notice no hesitation foot to the floorboards at high revs?
In the UK we can still get SU pump spares, but most people ( I think) move
quickly to replace the OE with a Hall effect solid state equivalent at
nominal cost. That will still give you a reassuring ticking noise, and mine
has now done about 30,000 miles without problem.
best of luck
I think it could also be that air is getting into your system between
the tank and the pump. I have a Midget (don't know if the B suffers
from the same issue) and have now gone through two tanks where the
metal pipe has corroded through at the join to the tank. This
effectively means that the pump is working on air - makes lots of
noise and will sometimes not be able to supply enough fuel. Could also
mean that fuel leaks out at the join.
Might be worth checking.
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