I tried to be brief before, but since there is a lot of only partially
accurate information being posted, I'll expand my reply. I rebuild SU
pumps, horns, and wipers as a part-time occupation, so I've seen it all.
Disconnect the pump from both inlet and outlet lines.
1) If it ticks strongly, there is nothing wrong with the electrics
(although a periodic cleaning of the points is always justified).
2) No ticking means that either there is no power to the pump (check
with a test light) or the points are stuck open (dirty, bent,
maladjusted, or broken). In the latter case, replace the points. Be sure
to count the number of turns it takes to take them off. Replace using
the same number of turns. Occasionally a broken wire is also the
3) Once the pump is ticking, wet your fingers and place one over each of
the inlet and outlet unions. It should be possible to cause the pump to
almost stop. If you can do that, the pump is OK. If the pump does not
stop ticking with the unions blocked, then the valve discs in the pump
need replacing or the valve seat is pitted (no cure for this short of a
new pump body).
Reconnect the inlet and outlet pipes to the pump.
1) If the pump now continues tick, it is leaking either fuel from the
pressure side (stuck open needle valve in the carbs) or leaking air on
the inlet side. Make sure the unions are snug at the pump or check that
you don't have a leaky fuel pipe.
2) If the pump stops ticking or significantly slows but does not deliver
any fuel, then there is a blockage somewhere. I usually make sure the
filter in the pump is clear and if not suspect crud in the tank or
supply line. Blowing backward from the pump inlet line back through the
tank will sometimes clear it. Also check any fuel filter in the inlet or
supply line itself for a blockage.
Burlen Fuel Services in the UK or Brown and Gammons supply a wonderful
rebuild kit for all variations of SU pumps. About $40, but using
exclusively that kit, I've never had a pump returned. The kit contains
EVERY moving part in the pump including new valves and many non-moving
parts, not just the common parts (diaphragm and points) contained in the
If the pump still refuses to work properly, contact me off-list. I
rebuild them for less than the price of a new one.
/// or try http://www.team.net/cgi-bin/majorcool
/// Archives at http://www.team.net/archive