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Electric Fuel Pump Maximum Pressure

Q. In your article titled "How to Change Your Electric Fuel Pump" you stated that fuel pumps are capable of outlet pressure around 90 psi. However when I search the web for data on specific fuel pumps most state their outlet pressures is less than 10 psi. Are you referring to a specific pump? If so, which one? I need a fuel pump for a non-automotive application that is capable of about 90 psi. Can you suggest a specific one?

Sincerely,
Steve

Electric Fuel Pump Maximum Pressure

A. Just about all automotive electric fuel pumps are capable of putting out, at least, 90 psi. A check valve is incorporated in the fuel outlet and a pressure limiter valve is located on the pressure side of the fuel pump housing with a return passage to the fuel inlet side.

When the pump is shut off, the check valve in the fuel outlet will close, therefore prohibiting the fuel from returning to the fuel tank via the fuel pump. The check valve will therefore maintain a pressure in the fuel lines called the "rest pressure".

The maximum fuel pump pressure (not fuel system pressure) is dependent on the calibration of the pressure limiter. If the fuel pump pressure exceeds a preset limit (for example a clogged fuel filter), the pressure limiter will open a by-pass to the fuel inlet side of the pump.

I have never changed the calibration of a pressure limiter valve or even know if it is possible to change the calibration. You might try getting a fuel pump from a junk yard and experiment with it to see if you can get it to the pressure you need.

Additional Information provided courtesy of ALLDATA

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