<The fuel system has a fuel pump, I think, so the lines are
under slight pressure when the car is running.
A. ALWAYS keep a fire extinguisher nearby.
B. Be ready to run like hell and call the fire department
   (and say goodbye to vanagon.)>

The lines are under more than slight pressure even when the car is NOT running
(believe me - I know!)

Here is a handy-dandy method for minimizing the amount of fuel that sprays
over your up-turned face as you disconnect the fuel line to, say, replace your
fuel filter, fuel lines, etc.
I read it in my newly-acquired Haynes manual and it's one of those things that
you could kick yourself for not thinking of earlier.

Locate your fuel pump relay (Bentley should be handy for this)
Unplug that sucker (carefully - it's easy to damage the socket by 'yanking')
Start your engine (it won't run long if at all)

By doing this you have just depressurized your fuel system and should avoid
having to perform step B above.
Step A should ALWAYS apply.

Of course, when you finish your work reinstall the fuel pump relay.

Sam Bateman
Fork Union, VA
'87 Vanagon GL