1. Haynes or Chilton Repair Manual: These aftermarket repair manuals often have detailed diagrams and explanations of the vacuum system. Look for one specifically covering your year and model (1984 Toyota pickup with the 20R engine). These are widely available online and at auto parts stores.
2. Online Forums and Communities: Search online forums dedicated to Toyota trucks, particularly those focusing on classic or older models. Sites like Toyota Nation or specialized forums might have members who have scanned or photographed a diagram from their own repair manuals or who can provide guidance. Be sure to specify the exact year and engine.
3. Local Mechanic or Toyota Specialist: A mechanic familiar with older Toyotas might have access to a factory service manual (FSM) or a readily available diagram. This is often the most reliable source, but will likely involve a small fee.
4. Microfiche: Dealerships *might* still have access to microfiche, which are essentially old-school digital archives of parts diagrams and service information. The likelihood of finding it and the cost are variables.
Important Note: The vacuum diagram will be crucial for properly routing vacuum lines. Incorrect routing can lead to poor engine performance, stalling, or even damage to the engine or emission system. If you're not comfortable working on your vehicle's vacuum system, it's best to seek professional help.
