SU electric fuel pump replacement
november 2007, while getting into the MGB to attend to
the Gazoline's monthly meeting in Bailly, France, my
engine stoped after one or two minutes idling. Once restarted, the car
could not accelerate properly. I first checked ignition and HT wires
but finally found the fuel pump did not operate.
A dead fuel pump is not a big issue but it can immobilize your car
driving far away from home. Fortunately, it happened to me while the
car was parked in its garage.
I lifted the MG, un-plugged the hose and checked for flow with ignition
switched on : only a few drops of gas came out, the pump was silent.
As petrol came after giving a few knocks on the pump, it became obvious
the points need replacement.
New point sets are available from parts retailers (part number :
AUB6106A ), but I decided to change the wole pump.
: Su fuel pump replacement
I did no
know anything about dual polarity fuel fuel pumps and I was scared by
the eventuality of a short circuit
on a fuel line device, so i made every measure to minimize
any risk :
main feed disconnected
- prevent from any fuel leak
- prevent any fire
Once lifted, the MG leans on its left
side. Fuel in the tank naturally goes on the side opposite to the fuel
Therefore, expect to collect around 1Litre of petrol.
Security first. The battery is
disconnected, the MG is on a stand, sand would stop an eventual petrol
flood, while fire extinguisher is immediatly reachable.
The Su pump's hot connection is
this this beige wire. The green wire is connected to the earth.
The old pump removal : petrol leaks from the hoses. The mounting
bracket is attached to the body with two 7/16 nuts
The new pump's outlet is clearly marked.
Beside is the earth connection.
The mounting bracket is fitted to the
new fuel pump prior to connect hoses.
Now the new MGB fuel pump is fitted to
the inner body. The bracket's lower nut (7/16)
is visible on this picture.
The collected petrol can be used to
clean the old fuel pump.
With ignition on, the new fuel pump starts its usual rattling.
Check your fuel line for any leak while the car is still jacked, and
once back on its four wheels with engine started.
While engine is started, expect some fuel to come out of the
carburettors overflow pipes. This is surprising, but it happens only