I had the same issue with my 67.
I rebuilt the carb. Replaced the fuel pump. Tried a different carb. Nothing changed.
I eventually found a small length of rubber hose connecting the fuel tank to the steel fuel line. The rubber had dried and had small cracks in it. Replacing the rubber solved the problem.
I think when the engine was running the fuel pump was able to overcome the small air leaks, but when only cranking at start up, it could not pull enough fuel.
I hope your fix is this easy.
Jim
|