[Shop-talk] High Hydrocarbons

eric at megageek.com eric at megageek.com
Mon Aug 26 18:06:01 MDT 2013


OK, if you remember, I asked about a 1991 2500 Chevy pick up that had been 
sitting for 5 years.

We got it running, and it failed inspection for hydrocarbons being too 
high (they were 466 and max allowed was 220ppm)
The CO%  was very low (.68)

So, I checked all the vacuums and they were good.  I changed the wires, 
plugs, rotor, distributor cap, and air cleaner.

After that, the HC were dropped to 240ppm (20 points too high.)  The CO% 
went up to .94  (still under the max of 1.20.)

So, I'm guessing that I can get it down with an additive or running really 
hot (or cold.)

What is the collective wisdom of what I can do next to get the last 20 
points?  Free is best.

Thanks in advance!


Eric P
"Be as beneficent as the sun or the sea, but if your rights as a rational 
being are trenched on, die on the first inch of your territory." Ralph 
Waldo Emerson 


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