78 Suburban surging then dies on long grade

[RyanAK]

Hey, Michael. Appreciate the input. I'm getting clean gas to the carb (I temporarily installed two clear inline filters for observation purposes... one on the frame rail and one between the pump and carb). When I shut down the hot engine the fuel disappears from the line between the pump and carb. Also, I did clean all surfaces and use the heat sink paste when I installed the new module in the distributor.

We now have all new rubber lines between the tank and pump. Cannot locate any issue with the steel lines.

This is a complete mystery. I have a suspicion that heat is playing a part in going lean/dry when the engine is under load, but that could just be a coincidence.

Carb rebuild kit from Cliff should be here today. But I'm not sure this is a carb issue. We shall see!