Fuel pump - continual slow tick

[MSM]

I have recently fitted a new electronic fuel pump AZX1308U in place of the original points version AZX1308. When I initially tested the new installation I was very pleased to note that after the initial rapid ticking, as it filled the float chambers, it then stopped; showing that there were no leaks anywhere. I left it for a couple of minutes before starting the engine and then confirmed that all the joints that were broken for the installation were leak tight.

Fast forward a couple of weeks, having finished some other work on the rear suspension, the time had come for a trial run to check that all was well with the rear suspension. My starting technique is to turn on the ignition and wait for the fuel pump to stop ticking before pulling out the choke and starting the engine. It was disappointing to hear the fuel pump continuing to tick after the initial rapid ticks. It was ticking roughly once per second.

Rechecking the fuel pump joints and the float chamber connections and drains showed no leaks. There was no petrol smell or drips on the floor anywhere. A quick run down the road and back was OK but with the engine off the fuel pump still ticks slowly.

Any ideas please?

[cactusman]

Either the pump is faulty or has a foreign body preventing one of the valves in the pump sealing properly or you do have a weep somewhere....is a float not sealing....look for fuel dripping from the overflow (SU carbs)

[johnetype]

I have the same model SU electronic pump and I get the same behaviour other than the gap between the "ticks" is 2 seconds or so.

I too have no visible leaks or overflows but it may be due to float valve bypass.

For an absolute check I'd plug the output from the fuel filter and see if the pump still ticks.

We may find it's normal behaviour for the electronic pump.

[mgcjag]

My ticking stops.......Give Burlan SU technical a call.....they should be able to help...Steve

[MSM]

Thanks for your replies.

I have spoken to Burlen technical today and they tell me that it is 'normal' for the electronic pump to click slowly once the float chambers are full but the engine is not running, it is maintaining pressure. Perhaps they should put a note in the instruction leaflet.

So there we are, don't worry about it!!