Vapor lock


I have a '56 Mercury that I have trouble keeping it running when it is warm outside. Since the car will restart when the engine cools a little, I think it is vapor lock. I have tried putting an electric fuel pump on it, but after 6 months the problem returns.


You may have to switch to the non-oxygenated fuel that the local hot rodders would use or for lawn equipment. Also you can try wrapping the fuel line over the engine with some type of insulator (used to use asbestos and aluminum foil). Carry a bottle of water and when it stalls, pour the water on the fuel line and if that does it, it is vapor lock.


Maybe the vehicle is flooding somehow


What makes you think it’s a fuel problem ?

It could be a faulty condensor or coil that doesn’t obviate itself until the ambient temperature increases. I’d check to make sure that you have an ignition spark next time the engine shuts down.


When my '80 Bronco had recurring vapor lock issues I replaced the normal in-line fuel filter with a 3 port in-line filter. The third line is a return line off the side of the filter. I had to build the return line back to the tank where I fastened it at the filler neck because that was easier. Instead of waiting by the hot manifolds to be used, the fuel would circulate back into the tank and not over-heat in the line. It worked for me.