I recently finished some recommissioning of a 1974 V8 manual. On it’s first test run, it broke down, there was no fuel in the filter. I managed to crank it and get it running and limped home. On the next run it misfired but didn’t break down. I left the car in the garage for a month or two until today. I had idling on the drive and after 10 minutes or so it cut out, again, no fuel in the filter. After much cranking it refused to fire so I checked that fuel was getting to the O/s carb by disconnecting the union. There was very little fuel there so I cranked the engine with the union off (it had cooled by then) and a fair splash of fuel emerged and the engine started with the union off! I switched off, reconnected and it ran very happily so I put it back in the garage. What do you think the problem is? Is it an air lock, worn pump, blocked pipes etc? It’s on standard carbs and manual fuel pump.