Re: Car won't start without priming carb

Posted by shinyhubcap On 2016/10/10 23:38:57

Good heavens - I am embarssed - having to pick on Kanter again !

I noted in an earlier post this evening how grateful we should all be for the Kanter people - their outstanding, responsible business practices & their knowledge.

So it really bothers me to pick on them a second time in one evening ! And I hope this dosnt discourage them from coming in here ! We often learn more from people we disagree with !

But the fact is - they are mistaken about fuel boiling. My suspicion is that a properly functioning electric fuel pump would solve his problem.

The simple fact is - modern fuel has a MUCH MUCH higher "Reid Vapor Pressure" than the of gasoline that existed prior to modern fuel injection.

Virtually all modern cars are fuel injected, and that means virtually all modern cars get their fuel under pressure from high-pressure pumps, typically located in the gas tank.

The more you pressurize fuel, the less it can boil away. So modern fuel engineers are free to provide a MUCH more volatile fuel. Makes for much easier starting on really cold mornings.

Again, my recommendation to ALL cars with carbs. and the old style "suction-type" fuel pumps, is that you mount an electric fuel pump as close to your fuel tank as possible, at the lowest point in the fuel line as you can.

That will save a lot of cranking. The electric fuel pump will immediately get gas to that empty carb. bowl. The old style "suction-type" fuel pump mounted on the motor, TRIES to suck enough fuel thru the lines, to get enough fuel into the bowl of the carb., to get the thing started. But it may not..especially since SUCKING fuel effectively lowers its pressure, making it more likely to "vapor lock".

For those who want to know more about the issue of "vapor lock" (which, again, is nothing more than the simple boiling away of modern gasoline in our old unpressurized fuel lines) I recommend you "google" the issue into the "SAE JOURNAL" ( a publication of the Society Of Automotive Engineers - excellent source to learn much technical information, often presented in layman's language.!)