Fuel issues 1955 TBird

[Annabelle]

Hi all. I recently purchased a 1955 TBird in Australia. The car is fitted with an electric fuel
Pump. Recently went for a couple hour run with no issue until coming home. Car was stalling
out at slow speeds. Seemed like it wasn’t getting fuel or flooding. It was a warm day 30 Celsius. I’m not sure if fuel was vaporising or is it was flooding. I limped home. However just wondering if the fuel pump should be left on or just on when starting it. There is a switch under the dash.
I’m not particularly mechanical and have read an article from here about poorly installed fuel pumps and vaporisation of fuel. Which may be the problem. Would appreciate your thoughts.

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[RMS]

Hello, the pump should be on when driving, if this is a carburetor setup there should be fuel regulator near the carb (which acts as a “gate” to same type of pressure a mechanical fuel pump would provide) . I’m going to guess with it running should be around 12 psi. If this is a fuel injection motor it should be a bit higher based on the injection specifications.

 

[doug7740]

Hello, the pump should be on when driving, if this is a carburetor setup there should be fuel regulator near the carb (which acts as a “gate” to same type of pressure a mechanical fuel pump would provide) . I’m going to guess with it running should be around 12 psi. If this is a fuel injection motor it should be a bit higher based on the injection specifications.

The fuel pump must deliver enough fuel to supply the requirements of the engine under all operating conditions. Normal pressure from a mechanical pump is 4-6 psi; 12 psi is too high of a pressure for a carbureted vehicle. Excessive fuel pump pressure holds the carburetor float needle off its seat, causing a high gasoline level in the float chamber, which in turn increases consumption. The pump normally delivers a minimum of 10 gallons of gas per hour, at top speeds and under an operating pressure of 4 to 6 psi. The highest operating pressure is at idle, and the lowest is at top speed.

It sounds like the problem that you are describing is vapor lock due to the ethanol that is in the fuel we purchase today. The following two articles addresses vapor lock & electric fuel pumps, and explains the effects of ethanol in the fuel we use today.

https://www.Thunderbirdforum.com/vapor-lock-and-electric-fuel-pumps/

https://www.Thunderbirdforum.com/revisiting-fuel-with-ethanol/

doug7740
1955 Thunderbird Blue

 

[RMS]

Doug7740 must be correct, I realized the only time I’ve ever dealt with electric fuel pumps on motors was where fuel demand exceeded the limits of mechanical fuel pumps. Good luck with your issue, looks like Doug7740 offered some good info.

 

[CSPIDY]

Remove a spark plug after you experience the problem, it will tell you if your engine is being flooded or starving for fuel.