Fuel pump - dirt in carb?

Post by **Dryad** » Wed Nov 30, 2005 12:09 pm

My '68 Minor has recently developed a fault; if I'm stuck in a traffic jam for any more than a few minutes the fuel pump starts to tick erratically, speeding up and slowing down as it does (for a couple of seconds) when you turn the ignition on after the car has been standing for a week or so. When this happens the engines starts to idle erratically as well, so I have to keep the revs up to stop it from stalling. Once traffic is moving normally it's fine again.

Any ideas? The only one I had that it was dirt in the float chamber.

Post by **rayofleamington** » Wed Nov 30, 2005 12:19 pm

the symptoms sound like fuel vapourisation but I struggle to believe that is the actual fault - it's Winter! Brr.

Therefore it is either something that gives similar symptoms or maybe you have a big overheat problem going on.

Post by **ColinP** » Wed Nov 30, 2005 12:27 pm

It would be worth checking the points in the fuel pump - clean them with a bit of card, and check the gap (30 thou').

As Ray says, it's unlikely to be fuel vapourisation, but check the filters are clean (remove & blow through).

(Has anyone ever had problems with the valves in the fual pump?)

Colin

Post by **Dryad** » Wed Nov 30, 2005 12:32 pm

The fuel pump is relatively new - about 2 years old. I don't think it's overheating as it hardly uses any water, and I reversed flushed the radiator and fitted a new thermostat about 3 months ago.

Post by **ColinP** » Wed Nov 30, 2005 3:56 pm

The fuel pump is relatively new - about 2 years old

Ah that's it!

Probably well worth cleaning the points!

My car had a new pump fitted as I bought it, after 3 years I had those problems - it seems that the new ones need a bit more tlc (try cleaning annually - just a bit of card between the points, or new points if needed).

NOW I keep a spare set of fuel pump points in the car.

Colin

Post by **Dryad** » Wed Nov 30, 2005 3:59 pm

Thanks Colin, I'll try that at the weekend.

Post by **bmcecosse** » Wed Nov 30, 2005 9:06 pm

Most likely the little float valve in the carb is leaking slightly - when you are driving the engine uses enough fuel to make it not matter - but when stopped the carb is 'flooding' - hence the poor running. So I suggest a new float valve asap !

Post by **rayofleamington** » Wed Nov 30, 2005 11:35 pm

Most likely the little float valve in the carb is leaking slightly - when you are driving the engine uses enough fuel to make it not matter

not a bad idea - it would also fit that it only happens when warm, as the engine would complain more about the extra petrol

Post by **Dryad** » Thu Dec 01, 2005 4:30 pm

I've got a feeling the carb might need a good clean out and rebuild anyway, so I might just get a kit from Burlen. Anyone know if a float valve comes with the rebuild kit?

Post by **bmcecosse** » Thu Dec 01, 2005 7:16 pm

Ask Burlen - but I would leave well alone and just get a new float valve. Not much to be gained by fiddling with the carb - unless you are going to 'Vizardise' it.

Post by **iddy** » Thu Dec 01, 2005 7:55 pm

Fuel pumps - Arrgghh.
Mine drove me scatty, it cut out in the most awkward places and wouldn't start until it was ready. I cursed it, I cleaned it, I thrashed it, all to no avail. I bought another one in the end. When I can bear to look at the old one again I'll take it apart and try and rebuild it for a spare.
If I think of it too much I'll be back on the tablets