1- Vaccum can for advance / retard timing (Unlpug, remove cap,  suck on it!!! you should see the rotor move!) the hose on the left of #1 is the retard one.
2- Fuel pressure test screw / divider for fuel flow each side of engine. Fuel pressure should be around 30psi. 3- Fuel pressure regulator. 4- Distibutor (Check inside cap if the center pin still as the spring) 5- Oil breather tower (O-Ring always leak) 6- Throttle body (There is no TPS on Vanagon!), check loose on this one by pulling up and down. Big screw on it is idle adjustement.
7- Idle / full throttle position switch / enrichment (listen for a CLICK!!!)
8- Vaccum line, check is not leaking 9- Rear engine bleeding screw 10- Brake booster line (is the one way valve working!!!) 11- Power steering high idle control 12- The infamous ECU temp sender, some call it the "Temps2" sender.
13- Sender for the temperature in the cluster 14- Oxigen sensor connector, it's green. 15- Fuel injector plug (NO, they don't have a specific position, you can mix them up!!!) 16- Ignition module 17- Idle control module 18- Ignition relay and fuel pump relay. They never go wrong.
19-Expension tank, the one you should care about!!! on it, a wire/ plug, yea!!! that is the infamous red light behind the temperature gage in your cluster... it's the coolant level sender. On 85+ the red light as 2nd fonction, it will also go on if temperature goes over 3/4. 20- The infamous fuel rail. Check my page on that scary subject