PVf44 61 fuel pump

[arcturus]

Hi,coming back from a run in the PV the car stuttered and came to a halt a«After a few attempts to re start I came to the conclusion that it was a fuel problem and had the car recovered to my home. I thought the quickest way to check was to lift the lid of the fuel bowls in the carbs and sure enough they were empty. I suspected a failed diaphragm so I removed the fuel pump and striped it down. The diaphragm was OK so I turned my attention to the check valves and as you can see in photo one appeared to be faulty. I have ordered a pump rebuild kit and intend to replace all the parts whilst the pump is off. My question is would the failed check valve alone cause the pump to stop supplying fuel to the carbs or should i be looking elsewhere.I strongly suspect the failed check valve but would like some confirmation. On previous occasions at high revs the car has stuttered but regained after I lift off,i had put this down to vapor lock in the hot climate.