I am having a problem starting my 78 vette after setting for a couple of weeks. I took the top off the carb and the gas was gone. I found no gas in the manifold. No smell of gas any where. Anybody have any thoughts. Thanks

 

One possibility is the inlet filter. There is a filter in a cavity right inside the big hex fitting where the gas line comes into the carb. If that filter and spring is incorrect or improperly installed the gas will siphon back out of the carb causing hard starting. Assuming your carb is a Quadrajet.

 

Also Q-jets have two plugs that have been known to leak. If that's the problem, they can be epoxied in using J-B Weld.