Ticking fuel pump

[warwick-steve]

Hi all,
An SU electronic fuel pump was fitted to my +earth BT7 some 16000 miles ago. Turning the ignition causes the pump to tick rapidly to prime the carbs. There would be no ticking when taking the car for a drive.
Recently the pump has started to click at 3-4 second intervals when running.
The car runs really well, smooth tick over and no smell of leaking fuel.
Is this ticking likely to be indicating a problem somewhere?
Appreciate your help
Steve

 

[Bob_Spidell]

'Ticking' is normal for a points-fired pump, caused by the throwover mechanism; all the electronic pumps I've had--several--made a 'thumping' sound, I think due to the solenoid retracting the diaphragm (the electronics don't make a noticeable sound). Pumping at 3-4 seconds when cruising at highway speeds sounds normal to me; maybe you just started noticing the sound? I can't think of anything that would just start making a new sound; usually, it's the lack of sound--particularly, a quiet engine--that indicates trouble.

 

[RAC68]

Hi Steve,

No. As I understand, it could be normally.

Your electronic SU pump uses a diaphragm and a throw-over mechanism similar to the points SU pump and will tick as the main difference is in the triggering mechanism (points vs electronic).

The fuel pump will tick slowly during a drive if the output pressure to your carburetors drops and the pump tries to resupply sufficient fuel to cause the needles to close and pressure to build over the set max pressure of the pump. More frequent ticking will be experienced from a leak in the system on the output side of the pump or if insufficient fuel is being supplied to the pump. In both of these cases, the pump is trying to provide sufficient fuel to pressurize the system with little success.

If your experience curve has grown to see 3-4 seconds between ticks as out of the ordinary and abnormal, then and only then would I begin to search for a fault in the system. However, depending on your fuel usage, 3-4 seconds between ticks could be normal.

Hope this helps,
Ray(64BJ8P1)

 

[warwick-steve]

Hi Bob and Ray
That is a great help. Thanks for your prompt reply.
cheers
Steve

 

[Healey Nut]

Both my BJ8s have electronic SUs and a 3/4sec tic is normal . IF it tics like crazy then your out of gas or you have a major fuel leak .

 

[Jeffry]

Mine ticked too loudly for me but what the heck, it ran. Well it wasn’t long before the ticking stopped and so did the pump. Stranded. Got new one and can hear it strongly when turn on ignition but can not hear a thing after. Get a new one or rebuild yours if you do that sort of thing.

 

[Patrick67BJ8]

Both my BJ8s have electronic SUs and a 3/4sec tic is normal . IF it tics like crazy then your out of gas or you have a major fuel leak .

Or, you have a vacuum leak between the tank and pump. I just repaired such a leak. Bad solder connection.

 

[John Turney]

Mine always ticks when turning on the ignition and filling the carbs. After the engine starts, I can't hear the pump ticking, but I can see a slight jiggle to the voltmeter needle when it pumps. Maybe the side exhaust has something to do with me not hearing it. :friendly_wink: