Fuel pump ticking

[ccooper174]

I have a 3.4 1962 Mk 2 and the fuel pump continues to tick when the carbs are full, the engine is not running and the ignition is on. I have changed the fuel pump and the new one operates as it should. What could be the fault of the old replaced fuel pump please.

[piman]

Hello Ccooper,

any thing that could allow the pressure to drop, e.g. one or both of the pump one way valves passing slighty, an air leak on the suction side of the pump. As the new pump is working correctly the suction line must be good but the inlet to the pump may have been slightly loose, something i think you would notice on changing the pump. A leak on the discharge would also cause that but woul be obvious from the smell of petrol and possibly fuel being evident. My guess is some dirt under one of the pump valves. I seem to remember that they are srviceable, but it's a very long time since I dismantled one.

Alec

[ccooper174]

Thanks Alec, I will try that.

[PPV]

I see you have made a comment about the AED to which I have replied. This seems to suggest that the front carb inlet valve is not shutting off and hence the fuel pump continues running and also causes the AED to overflow.
Regards,

[ccooper174]

Hi PPV,
Thank you for your replies I will look at the front carb float height settings and let you know how I get on.
Thank you again,
Chum Colin.

[ccooper174]

I have renewed the seat and needle but the AED unit still keeps leaking petrol at odd times.
I have obtained parts from Burlen to convert the carbs to manual choke and let you all know how I get on.

[PPV]

It is strange because the AED does not actually isolate the fuel itself (only the needle valve will restict it if no air flow through it), the solenoid isolates the air/fuel passage so the fuel flowing is just mainly dependant on the level in the main float chamber. Was the replacement float chamber valve one with the soft 'black' seat? And did you check that the pump now shuts off after replacing the needle valve?
Regards,

[ccooper174]

Hi, the needle valve has the rubber black seat and the pump shuts of as it should, but the AED unit still leaks a small amount of fuel when the engine has been left to tick over for about a minute, the idle stutters the fuel leaks out, then the idle goes back to running as it should for about another minute then it leaks again.
I am now waiting for Burlen to send the correct parts for my conversion to manual choke, then I will report again when I have fitted the parts.

[PPV]

Does the pump cut off when the ignition is on but the car is not running? If not then the valves are passing for some reason. If they do shut off and then you run the car and the AED leaks then the float levels are set wrong, (check how to set them in the manual).
That should sort it.

[ccooper174]

I have now more or less just finished converting the carbs to manual choke, all seems to be OK. I have just got to adjust and set and balance the carbs. The ticking fuel pump may have been the connection from the new petrol tank not sealing properly. I had to clean the inside of the threads to the union nut, as when the manufacturer in China sprayed the new tank, the union was not covered. Tip test the threads before fitting the tank.
I will report again when I have run the car and balanced the carbs.