MG Car Repair: MG midget fuel pump tick, new tank, mg midget

Question
Hello,
I have a 1972 Mg midget that I recently purchased.
I was driving it around for the first month with no problem.  
However, today as I inserted the key into the one position, something odd happened.
Usually, the fuel pump ticks a few times and then stops.  At which point I start the car using the choke.

This time, the fuel pump wouldn't stop ticking.  Instead it sounded like a continous ticking.

I was wondering what the problem was.  It has a new tank, new lines and I checked the fuel filter which is half full.  The car does turn over and start but shortly after stops.

Any help would be greatly appreciated.

Rico

Answer
Hi Rico,
When an SU fuel pump first clicks it is pumping fuel and when it stopped it meant that the float chambers of the carburetors were full and the float needle had closed off the fuel and the pressure then builds up to a point that the pump stops or slows down to just an occasional click.

When the pump clicks very fast it is drawing air. If it just clicks at it's normal first start-up speed than it is pumping fuel out somewhere. Either on the ground or if a float is stuck it can be pumping fuel into the engine and air filter. If this were the case the engine would run very rough and blow black smoke out the tail pipe.

At the time your engine dies if it is blowing black smoke and running very rough you need to open the float chambers and correct what ever is wrong there.

At the time the engine dies it is running good and it just cuts off and the pump has been clicking very fast then the pump is drawing air in and that has to be between the pump and the end of the pick-up tube in the tank.

Howard