Hot weather start issue....

[I am Groot]

Cars running really well no problems but after say 30 miles engine temp normal i stop the car to refuel come back five mins later car starts ok but won't run just stalls as if its run out of fuel! Let the pump run turn key start up and rev loads , car runs really well again. Is it the engine and external temp evaporating the fuel in the carbs creating a temporary fuel starvation? The carbs are rebuilt with new enriched needles and the pumps a new ld parts electronic and i haven't had any problems until very hot temperatures today. Any ideas guys? Are strange things happening in the heat?

[DJT]

You say the carbs are rebuilt. Have the temperature compensators been set up correctly?

[I am Groot]

I hope so Dave was professional job. Last time I had trouble with temp compensatory valves it wouldn't start at all ! This is different as it does start but after loads of Reeves like I have to build up the fuel level again!

[Stagdad]

Reving it won't build up the fuel level in the floats but it will circulate coolant and maybe it's getting rid of the heat soak enough that the engine will run properly

[mallardstag]

try stopping the engine by pulling the inertia switch and waiting for fuel exhaustion. if it starts ok after this then maybe it's leaking float valves.

[I am Groot]

Reving it won't build up the fuel level in the floats but it will circulate coolant and maybe it's getting rid of the heat soak enough that the engine will run properly

It's on an ewp so circulates on ignition on. But I think you might be right Stagdad so I'm going to let it circulate for a longer period before trying to fire. That could do it. Did I see a post from Tony Hart something about the float chambers had to be cooler or something.
thanks
nigel

[I am Groot]

VENT valves! That could be it.

[edd]

The chambers can get so hot causing evaporation . I was told if this happens pour some water over to cool .
it's happened to me and it instantly solved it.

[I am Groot]

VENT valves! That could be it.

Vent valves are ok must be the compensators. Going to investigate.

[Rubce]

Hi Groot

What was the result?

Regards

Bruce

[I am Groot]

Hi Groot

What was the result?

Regards

Bruce

Hi Bruce, the one compens ator was tight and slow while the other loose and therefore faster to open. Being honest it was difficult to be really accurate about temperature and opening but what i did do was adjust so that both opened together and at same rate. It definitely improved hot start but hasn't solved the problem entirely. The performance is improved notably though and a little niggle is that the cold start needs choke a bit longer than it did before and needs nursing a bit more. I dont think actually theres much wrong with the cars its just a hot weather phenomena due to modern fuel and old carbs! Raining so not tried her in cooler temps yet.