Very difficult starting engine after refueling. Check Engine Light diagnosed as Code 4047 Evap.Leak:need to replace purge valve and rear shutoff valve, $325. Question: what are these parts'function, and where are they located in the vehicle ? A DIY job ?

Because starting engine after refueling is so difficult, with many attempts (and much 'probably ineffectual' fluttering of accelerator pedal)I have resorted to"hot" refueling, which means with engine running. Engine begins to chug upon removing gas cap, water droplets are expelled from tailpipe, but it's only for the few minutes until refueling is completed. With gas cap replaced,engine returns to normal idle by the time I'm ready to drive away. Is this OK in the short term, or a BAD thing to do ? Thanks for your advice.

I wouldn't worry so much as the car catching fire as the pump and station going up also :)

When you remove the gas cap with the engine running, the EVAP system will produce an error - gross leak.

The J hose is easy to replace and probably cracked, causing your current problem. The charcoal cannister is probably filled with liquid gasoline instead of just fumes. Fixing the hose should fix the cannister and the evap error code.

Just take a look, easier with the rear wheel off. The hoses in question are next to the fuel filter. Pull off the J hose and inspect for cracks at the short end.

Klaus
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Praying for Cynthia Amendt, heaven bound

BAD! Those vapors can be ignited and make quite a big explosion.

In that picture below, try disconnecting the EVAP line from the purge valve and the one-way valve just before the engine block (the section highlighted in red). Then try fueling and restart your car.

The valves in question are above the right rear axle, the charcoal cannister lookes like a box and the purge valve is just before it.

If you fill the tank too full, that will also cause problems with liquid gasoline getting into the vapor line. Never add more past the automatic shutoff.

Klaus
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Praying for Cynthia Amendt, heaven bound

In my S70, the charcoal canister is in front of the left front wheel well under the airbox. The purge valve is then just behind this highlighted line, the black box on the radiator shroud.

I don't know whether or not the AWD's were different in this respect, but as I understand that's where they moved it to on the newer models (sorry, the pictures stolen from a PCV system repair, I don't know where I saved the original on here or I'd draw you a new arrow).