Hi there, I have recently purchased a 1972 Fiat 500F which is totally standard. An issue I am having is that every morning I go out to start the car, despite having a decent amount of charge in the battery (I use it almost daily when I'm at home) the fuel is returning to the tank and I'm having to use all the charge spinning the engine over to draw the fuel up; so much so that every time it requires a quick charge to get it going.

Does anybody run a 'one way' valve in the fuel line somewhere to prevent this?

A couple of points to note Donald
1st there should be enough fuel in the carb float chamber to start the car
2nd the petrol tank is higher than the fuel pump and petrol is fed to it by gravity. If you have to disconnect the fuel line before the pump for any reason you will drain the tank if left long enough.
If you have an accomplish I would disconnect the fuel line where it enters the carb and put it in a jug. Turn the car over and see if fuel is going into the jug. If it does you have another fault. If it doesn't then your pump is probably at fault
Damian

Hi Donald I agree with what Damian says. If you have an in line filter and this is what you are using to come to the conclusion that the fuel is draining back to the tank because it is empty each morning, then this is perfectly normal. It will only fill halfway even at idle, you rarely see it full up.

Tony

DonaldMHM said:

Does anybody run a 'one way' valve in the fuel line somewhere to prevent this?

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One way fuel filters are available either that or you could park facing up a hill.

I'm with the others though - check your fuel pump and make sure the carby isn't leaking.

Chris

The mechanical fuel pump has a non return valve in it anyway. If fuel is draining away from the carb, then I would have a look at the valves in the pump. Another non return valve shouldn't be necessary.

The float chamber in the carb should remain full, could you have a leak in the bottom of it?

My two cents worth
Chris

looigi said:

The mechanical fuel pump has a non return valve in it anyway. If fuel is draining away from the carb, then I would have a look at the valves in the pump. Another non return valve shouldn't be necessary.

The float chamber in the carb should remain full, could you have a leak in the bottom of it?

My two cents worth
Chris

Click to expand...

True Chris I forgot about the return valve in the pump. If I remember correctly there is a bowl in the pump so any fuel normally between the pump and the carb normally drains back to the fuel pump bowl. So there really shouldn't be a problem getting fuel to the carb, so it points to the pump being faulty, possibly?

Tony