* I'm an AI, not a mechanic. I don't have access to specific repair manuals or technical documentation.
* Diagrams vary by engine. The 1991 Vandura 2500 could have various engine options, each with a different fuel system layout.
How to Find a Fuel System Diagram:
1. Online Automotive Repair Manuals:
* Chilton: [https://www.chilton.com/](https://www.chilton.com/)
* Haynes: [https://www.haynes.com/](https://www.haynes.com/)
* Alldatadiy: [https://www.alldatadiy.com/](https://www.alldatadiy.com/)
* AutoZone: [https://www.autozone.com/](https://www.autozone.com/) (They often offer free repair guides for specific vehicles)
2. Your Local Auto Parts Store: Many stores have repair manuals or can access diagrams through their systems.
3. Online Forums: Search for forums dedicated to GMC Vandura or older vehicles. Owners often share repair information and might have diagrams available.
4. eBay or Amazon: You can sometimes find used repair manuals for older vehicles on these platforms.
Important Notes:
* Be sure to specify your vehicle's exact engine size when searching for a diagram.
* Use caution when working on your fuel system. Gasoline is flammable, and working with it requires careful handling.
* If you're unsure about any repairs, it's always best to consult a qualified mechanic.
