i was having this problem in my 87 wolfsburg weekender.

at first it was running rough and stalling when backing up in the morning.
it increased intermittantly and a gas smell was added, then my 02 sensor
light came on and one evening i lost power and bairly got her home.

my mechanic drove it 2ce and it was fine.   he was about to have me pick
it up
when he gave it one more try.  down the road a mile it died. he towed it
back
to the shop where he checked the injectors and sparkplugs as it was
started.
he was immediately covered with fuel as was the engine-but nothing had
come
out of the injectors or plugs.  the oil was also full of fuel.

he found that all this time the fuel pressure regulator was starting to
fail.
if it hadnt gave out completely at this last testing,  he says he may not
have found it.
he said this was a recipe for a van fire.

so, the fuel hoses will be my next parts change for him!!

relieved,
arlene sondergaard