My 1984 vanagon engine was rebuilt in December 1999 because the
idle hydrocarbon reading was over 220.  The engine now has about
30K miles on it and the idle hydrocarbon reading suddenly jumped.
Only 3K miles were driven in the last two years.

Does anyone have ideas on what may have caused this
and suggestions on how to repair?

The results of the last four emissions tests follow:

high rpm  low rpm

2015
hc 93     165
co .66     0.3
co2 13.8  14.1
02  0.01   0.0

2013
hc  43     31
co .11     0.1
co2 14.7   14.8
o2  .42    .15

2012
hc  35     62
co .20     0.02
co2 14.3   13.0
o2  3.31   3.83

2011
hc  33      75
co  0.09    .01
co2 14.3    12.5
o2  .51      3.13

Thanks!

--
William

Live a balanced life. Learn some and think some, and draw and paint
and sing and dance and play and work every day some.
-Robert Fulghum, author (b. 1937)