Fuel pump not working is not vapor lock
Vapor lock is when the components are so hot the fuel
Is boiling into a vapor inside the lines and components
Even with empty line and filter the carburetor will have enough gas in the float bowl to start the vehicle
But anyway
Not starting hot sounds a lot like a problem I had
It was the coil going bad
The internal insulation breaks down and become heat sensitive so you get too weak of a spark hot while the starter is dragging the battery voltage low
I could roll start the truck fine
But no amount of cranking hot would work
New coil fixed the issue instantly
-s
