Re: TrevorK's 1955 Packard Patrician

Posted by HH56 On 2017/7/20 16:59:12

Not likely. The only item that directly sees fuel pump pressure is the needle valve operated by the floats. Too high a pressure would result in fuel leaking past the valve as it tried to close off the flow. In that instance there would be flooding or leaking fuel from the carb.

The accelerator pump is supplied from what is already in the fuel bowl and never sees pressure other than the level of fuel in the bowl. If you have an electric pump those can cause problems with overwhelming the needle valve and need to be within the proper range but still would not affect the acc pump..

Pressure specs for the mechanical pump is 3 1/2 to 5 1/2 psi. If there is an electric pump mounted in the rear and pushing thru the fuel pump and filter as most are then it should have an output of, or be regulated to be, in the 5-9 psi range. Several have added electric pumps which can be turned on when needed to prime the carb after a long sit or to alleviate vapor lock situations.

I wonder if there is some kind of burr or otherwise rough or damaged surface in the acc pump chamber and that is cutting or tearing the accelerator pump.