[Mgs] SU Fuel Pump Question

Paul Hunt paul.hunt1 at blueyonder.co.uk
Sat Apr 10 08:09:36 MDT 2010


Where are you applying power and ground when it "will click repeatedly if I
apply power in a rapid fashion"?  Where are you applying 12v and ground when
it doesn't  click at all?  If it clicks *once* when you apply power and
ground to the 12v and ground spades, then the points are stuck together,
either welded or maladjusted.  If you can lift them apart, it is probably
adjustment.  If the points are pitted and spiked the spike needs flatting
and both faces burnishing, then the adjustment (the 'throw' of the points
when the diaphragm is manually operated) needs to be checked.

It's nothing to do with fuel (unless it has turned to treacle).  The pump 
doesn't need to be primed.  With the points correctly cleaned and adjusted 
the SU pump will operate perfectly for many many years and tens of thousands 
of miles, which is why probably the majority still have them.  The points 
started sticking on my roadster giving the 'clicks once' symptom you seem to 
have.  I had a new spare and fitted that by the roadside, then cleaned and 
adjusted the points at my leisure.  Then the aftermarket pointless 
electronic pump on my other MGB started playing up intermittently, so I put 
the old pump on that and it has been working without a problem every since 
(some years now).

PaulH.

----- Original Message ----- 
> I have a SU fuel pump that will click repeatedly if I apply power in a
> rapid
> fashion, but will not click at all if I hold a jump wire to the ground
> terminal.


More information about the Mgs mailing list