Instead of a single diagram, you'll need to consult multiple sources:
* Factory Service Manual: This is your best bet. A 1985 Corvette service manual will have detailed diagrams of the vacuum and emission systems, showing the various vacuum sources, actuators, and sensors involved. These diagrams might be spread across several sections. You can often find these manuals online through various automotive parts retailers or used booksellers.
* Wiring Diagrams: The vacuum system's operation is often intertwined with the electrical system, especially with the TPI's electronic controls. Wiring diagrams will show how various sensors and actuators are connected, providing context for the vacuum lines.
* Component-Specific Diagrams: Individual component diagrams for things like the EGR valve, fuel pressure regulator, and other vacuum-actuated components will show their vacuum connections.
Why no single diagram? The complexity stems from the computer controlling many functions previously handled by vacuum. The vacuum lines are used for less direct operations.
In short, there isn't a single, simple vacuum tube diagram for this engine. You'll need to piece together the information from a comprehensive service manual and potentially other resources. The service manual is absolutely crucial for accurate understanding.
