Re: 1938 v12 Touring Sedan Vapor Lock?

Posted by Owen_Dyneto On 2011/4/21 17:23:57

A couple of questions and a couple of thoughts:

What part of the country are you in, or what are the temperatures at which your problem is encountered?

What kind of driving conditions bring ont he problem?

Where in the fuel delivery system is the electric pump located?

What's the pressure of the pump?

What's the coolant temperature when the problem arises?

Are you pushing thru the mechanical pump or is it bypassed?

Is the electric pump plumbed with a return line?

Excellent suggestion about the gas cap vent!

My experience with Twelves is fairly limited, but I think generally they are not particularly prone to vapor lock. Have you eliminated a bad (or bad set) of condensors or ignition coils - symptoms have some similarities are are occasionally confused with each other.

Vapor lock (if that's the problem) is much more likely to occur in the suction side of the system because the boiling point of the fuel is depressed on the suction side, and elevated on the pressure side. Any close proximity of the fuel suction line to the exhaust system?