Fuel Starvation

[Fastededdie]

Hi on my 260 I have triple 40s Webers they are tuned correct but I am having a fuel starvation issue. Starts up fine and fuel coming from the pump. As soon as the engine gets hot it splutter and runs out of fuel. This is normally only after about 15 mins of driving. I know we can get heat issues with the carbs but surely not after such a short period. Shall I re link the return line ? though I believe we do not have to with webers. I do have a fuel adjustment gauge set at 3 but Iv tried all sorts of combinations with this and no change. Is it a vapor lock? not sure. fuel line block? Don't think so as on initial start up there is no issue. Any ideas? Thanks

 

[Rob Gaskin]

Maybe vapourlock maybe fuel filter.

 

[Fastededdie]

Maybe vapourlock maybe fuel filter.

Hi Rob took off the fuel filter thinking it was the issue but just the same.

 

[jonbills]

can you describe what happens in a bit more detail? it runs out of fuel, so it stalls?

 

[TB24O]

Hi fastededdie,have just put triple webers on my 240z and same sort of thing has happened to be twice after about half a hour on fast driving, car seems to start to die on you, thought it could be heat soak/ vapour lock but that normally when you try to start car!
What i think it could be is the petrol in tank is getting vacuum locked, try this undo petrol cap and release pressure, don't know if cap has a breather on it?
Anyway let me know how it goes?
Regards Tim

 

[Texasroadrunner]

Hi fastededdie,have just put triple webers on my 240z and same sort of thing has happened to be twice after about half a hour on fast driving, car seems to start to die on you, thought it could be heat soak/ vapour lock but that normally when you try to start car!
What i think it could be is the petrol in tank is getting vacuum locked, try this undo petrol cap and release pressure, don't know if cap has a breather on it?
Anyway let me know how it goes?
Regards Tim

I also have Triple DCOE 40's on my L24. When it's fully warmed up after some spirited driving, I can get some hot idle issues. Sometimes when I come to a stop it can die. It restarts fine. Also, I can take a left-hand sharp turn at speed with no problems. Right hand hard turns sometimes give me a bog in the middle of the apex when I'd rather have power to exit the corner. It's disappointing. Float levels are correct as I can make them. My fuel pressure is normally between 3 and 4 psi. I have a Carter electric pump by the tank that is factory set at 4 psi, so they say. In other words, a pressure regulator is not necessary.
My '72's previous owner had removed the vapor collection tank and hoses and capped the fittings on the tank. That was making the tank build pressure on warm days. When removing the cap to fill it, the pressure blown out was substantial. On close inspection of the tank cap, I see a one-way check valve that will allow air in but not out. I decided to drill a .75mm hole through that valve. No more tank pressure issues now. It will seep a little fuel out if the tank is full and I make hard left turns. So I keep it about 3/4 tank at the most.

 

[moggy240]

Have you checked the piping for the fuel tank vent hose, it will be behind the rear quarter plastic panel.