Hi there,
I think it's just running a little rich. Notice that the high speed HC is also way high, although it did pass. Normally you would expect to see the high speed HC under 50 or so, and the idle HC under 75. There are several things you could do, one being raising the idle speed a bit, which might help things. You might look at the gasoline mixture - maybe it doesn't have enough wood alcohol in it - HINT, HINT My car doesn't even have a catalytic converter on it, and the HC tests at under 75 even at idle, without any "help". You might also verify that the ignition timing is correct at idle, and possibly retard it a degree or two. You have too many unburned hydrocarbons in the tailpipe. As has previously been stated, this is many times a misfiring plug - make sure the plugs are correctly gapped - too close a gap will cause misfiring at idle.
If you have access to a 5 gas analyzer it is very easy to play with things and see what helps or hinders.

Good luck with it!

Richard Wooldridge
'82 300D/4.3L V6