Fuel pump - what's normal clicking frequency?

[worrasf]

I became the proud owner of a 1963 Traveller a few weeks ago and am absolutely delighted. Starts first time every time and so far reliable including the 150 mile trip to bring home to Yorkshire. My question is about the SU "ticking" fuel pump. Mine "cycles" very frequently - it can go from once every few seconds to a rapid burst where is clicks rapidly for 5 seconds or so repeatedly - is this normal? There are no (obvious fuel leaks), I have cleaned the internal filter (which actually did'nt need cleaning but there were a few bits of rubbish in the base of the drain bolt). As I say she starts first time, I can push the choke home after about a minute and drives smoothly so no evidence that the pump is not working properly. I have yet to clean the points. I actually bought a new set of points and then read the maintenance manual - not sure I want to take the old ones out and then not be able to fit the new ones correctly. I think I may have read a thread that a worn float needle might cause this "problem" but may be wrong.

Anyway, if folk think that this is nothing out of the ordinary I will leave well alone.

Steve

[polo2k]

sounds fairly normal. might be worth taking the 3 flat headded screws out of the top of the carb (where the fuel pipe goes in) you will then be able to remove the top and check the valve in the top of there. If that valve if sticking closed then opening, you will get the symptoms you described.

I used to live near headingly and whenever I needed engine bits always ended up in bradford. there is a million little mini speciaists, just look in the phone book.

[Rob_Jennings]

it will tick according to fuel demand.... higher the engine revs or the more the engine is working (hill climbing) the more fuel hence faster ticking. It will also tick rapidly to fill the float bowl when you first turn the key otherwise a gentle once a second or so when driving is normal.

If you gets bursts of tick there are a few possibilities:

if its getting hot under the bonnet then the fuel may be vaporising in the pipe and the pump will tick rapidly until it can draw fuel, this can be reduced by shielding the pipe from the hot exhaust opposite it (clever design but not really that critical unless its very hot under there)

if the float in the float bowl is sticking then you may find that it is emptying until suddenly it unsticks and so there is a sudden demand, carefully clean out the float chamber and fit an inline fuel filter (good idea to do this anyway to stop rubbish from the tank reaching the carb)

if the point are giving up then the behaviour is to stop ticking until you hit it ;-) so its unlikely to be that just yet. You could remove the top of the pump and run a bit of fine emery paper between the points to clean them up.

[worrasf]

Thanks - sounds like the float needle is likeliest culprit - already have an in-line fuel fuilter fitted. Have ordered new float/needle from Bull Motiff. Will feedback when arrived and fitted.
Steve

[overider]

Hi Worrasf, hope you sort thing out with the carb.
If you would like to join us at the West Yorkshire MMOC, please come along and make yourself known. We are a good cross section of people of all ages.
We meet on the last Wednesday of every month at the Cleckheaton sports and social club just off j26 (Chain bar) of the M62, it’s the junction of the M606 & A58. If you have any problems with your Moggy they is always someone that can help or advise you. We also have a good collection of club spares and tools to help all members. Its always nice to see new members and there cars.
If you need any more info about the club just PM me.

[rayofleamington]

if the point are giving up then the behaviour is to stop ticking until you hit it

Not always true!!
Failing points will make poor contact and the pump will stop running. The rapid burst can come when a bit of vibration restarts it.
I had one that restarted with the vibration of opening the bonnet (it sits near the bonnet stay).

the petrol pump points should be checked as soon as possible when you've aquired a new Minor - replacing knackered ones can prevent an annoying breakdown.

[jaekl]

I cut my teeth on the fuel pump. Another item that may cause it is a small hole in the diaphram. It can be fine when cold but after driving a while in the summer, it will start pulling air. However, if it's just an occasional burst, I'd go with vapourizing. I have a plastic fuel line on my truck since I made a larger tank on (back in the eighties) and I can see the bubbles forming in the fuel about 8 inches away from the pump. Shield the fuel line and a bigger line could reduce the negative pressure on the fuel. Now we know why pumps were moved back to the tank.

[bmcecosse]

Or just move the pump lower down but still at the front. It's the 'lift' that seems to cause some cars a problem - although it's not a problem I have ever experienced.

[worrasf]

Thanks for the invite Overider - I'll do my best to drop in to one of the meets.
Steve<br><br>

[worrasf]

All sorted - new float and needle did the trick