[wilf leek]

I have the same fuel pump. I think that at least one of the symptoms you describe is actually not a fault.

That is the speed with which the fuel pressure decays when you switch off. Mine too runs down to zero in 1 or 2 seconds. I do not believe there is any non-return valving in the Carter pump, thus fuel flows backwards easily through the gerotor gears when the pump stops.

Apart from that, I get 5 psi at all times. First thing I would check in your shoes would be the gauge.
After that - look for a vacuum in the tank.


HTH