I have an early 70's car with a rear mounted fuel pump which has failed. I have bench tested both a Bosch replacement and a GSF pump and both flow at 1.5 litres in 25 seconds. On fitting each pump in turn to the fuel lines neither pumps fuel when asked. There is a free flow of petrol along to the pump inlets but neither pump pushes fuel from it's outlet into free air. Can anyone explain this odd behaviour - perhaps I have missed the blindingly obvious.
Any suggestions most welcome.
Any suggestions most welcome.