Just to close out the issue: I had the Weber carburettor stripped, cleaned, rebuilt and tuned on car. Apart from cumulative dirt/grime etc we found the only obvious thing was the float was out of correct calibration. The fuel hose from the pump to carburettor was also replaced. Fuel pressure checked OK as did the vacuum. Took the car for a 300km drive on some windy hilly roads last weekend and it didn’t miss a beat! 🤞
