Petrol evaporation

[morrisminor]

Has anyone had any trouble starting their car( Zenith 26va) in this hot weather, it will not go on handle unless I manually fill the float bowl then it fires first time, it appears the priming lever in the fuel pump doesnt work.Before filling it, the bowls almost empty after just standing 24 hours, once running its fine

[Dave Mann]

What you report doesn't surprise me given this lovely weather we are having, suggest you fix the priming lever I haven't experienced it with a gravity feed car.

[Steve kay]

An interesting question. In the very hot weather my Ruby priming lever gives the feeling that it doesn't work. Lots of turning with the handle or spinning with the starter and the mighty machine fires up easily. I had attributed this to modern petrol which can certainly feel volatile so does it easily vaporise. Did Longbridge drawing office have much experience of mid to high twenties temperatures?

[squeak]

If when you first try the manual priming lever you find it has no travel and therefore no pumping action, grab the crankhandle ang give the engine exactly one turn. And try priming again. 
OR leave the bonnet open overnight to vent the engine heat.
Just an idea       cheers   russell

[morrisminor]

Thanks for the replies, what could be wrong with the lever ? as with the float bowl off I've pumped it at least 20 times, nothing, on the handle moreless straight away

[AustinWood]

Have you tried Russel's suggestion?
If the camshaft stops with the internal pump lever fully depressed then the priming lever won't work.
You should feel the spring pressure when operating the priming lever.

[John Mason]

On my Ruby the return Spring is broken on the priming lever so I have to make sure it is in the fully down position other wise it will not pump petrol and I have starting problems similar to what you describe. Also with the heat we have been having my garage has had that wonderful old fashioned petrol smell which has slowly diminished as the warm weather as gone on and on. There is no petrol smell now as all the ethanol has evaporated away but this also makes for difficult starting. I'm
John Mason

[Bob Kneale]

Have you examined the gasket on the top of the pump? It may be that the cork or rubber material is porous and allows petrol to leak back to the tank over a period of time. I've replaced this gasket with an 'o' ring of appropriate diameter. The hot weather probably isn't helping. Check that the bolt on top is sealing adequately as well. I use a 1/4" Dowty Bonded Seal at this point.

Hope this works for you