Fuel Hungry-- after shut down • The Dodge Challenger Message Board

by **matt** » 12 May 2007 12:31

My 70 440, is eating fuel even when it is not running. I have a glass fuel filter going in to my carb, and I have realized that after I shut my engine off, the carb continues to suck fuel, and disperses it as vapor. I have noticed this, and it makes me wonder exactly how much fuel I am wasting from this vapor loss. Is this a common problem? I was thinking about putting a valve in the fuel line, so that when I am done driving I can just shut it so no fuel can be sucked in to the carb. Is there any other way to fix this problem?
Thanks-- Matt

by **Eddie** » 12 May 2007 14:13

I dont fully understand your "problem", you are having trouble starting it? A carb is a pressure differential device nothing "pushes" out fuel except the accelerator pump and thats momentary, do you have an electric fuel pump in line, if so, do you have it regulated? It is possible to have a leaky fuel bowl or crack in the base, or dirt/debris obstructing a fuel passage enabling raw fuel to leak into the throttle opening. How does your car run? BTW, I would ditch the glass filter, youre asking for trouble their with a hot engine :shock:

by **dave-r** » 12 May 2007 14:58

I think what you are seeing is the fuel boiling in the fuel line. When you shut off the engine the heat soak is boiling the fuel.

The answer is to run your fuel line away from sources of heat (I bet the fuel line is near the exhaust and i also bet you are running headers)

You can also insulate the fuel line.

If you find the carb is getting hot enough to boil the fuel in it (feel the fuel bowl and listen for boiling) the use a thick insulating carb-to-manifold gasket and if you have headers block off the heat riser that runs through the intake manifold.

Also listen to Eddie and get rid of the glass fuel filter!

by **Jon** » 12 May 2007 15:27

I have heard that a blown power valve will cause fuel to leak into the manifold.

by **matt** » 13 May 2007 19:30

thanks guys, yeah I think I wil get rid of the glass filter, it is running up along the valve cover, and it does get quite hot after the engine shuts down. I will prob re-route the gas line to get ti away from the heat of the block, and headers.
Well thanks for the help :V8:

by **dave-r** » 14 May 2007 9:27

If the fuel line runs over the engine that is the problem for sure. It does not take much heat to boil petrol.

Also the cooler the fuel the better the power. :thumbsup: