California Smog/Emissions Test Failure, High HC

[Prime]

I'm in California, so you guys here will know the drill. I'm a test-only bitch of the state, and so I'm kind of limited in my options here. As I'm also limited in funds for sending it to a Test and Repair shop, I thought I'd come here first.


Here's the gist: 1990 Nissan 240sx, swapped SOHC for a 91' KA24DE. Roughly 200k miles on the clock (didn't write down from donor car).

What I have, asterisk (*) indicates new since failure
New Catalytic Converter
*New Spark Plugs (NGK Platinum, properly gapped)
*New Plug Wires (Bosch, I know, I know...)
New Rotor and Cap
*New Injector O-Rings (Nissan OEM, not 3rd party)
Injectors all test within spec
Compression 149 +/- 2 across the board
Not burning any oil that I can detect
Timing set 15 degrees BTDC as I heard that helps with HC.

I was told I had a slight misfire at idle, which is why I've changed the above components. Now, for the numbers

@idle (650 per fsm)
%CO2 14.9 (Pass)
%02 0.2 (Pass)
HC PPM 169 / MAX=120 (FAIL)
%CO .11 / MAX=1.0 (Pass)

@2500~RPM
%CO2 14.7 (Pass)
%02 0.3 (Pass)
HC PPM 72 / MAX=140 (Pass)
%CO .37 / MAX=1.0 (Pass)

So... any ideas?