Sounds like the ICM (and line) are plugged correctly. On the ICM subject, "randomdude" is mistaken above where he says: "Yes I think you would want to retard timing (closer to TDC) since thats what you're doing by plugging the module ..."

The vacuum plugging does NOT retard the timing. All it does is prevent the initial overadvanced timing as you open the throttle. See original post here, for technical details.

Also, in your first post above you said:

"Well, I have done the following since the last test:

new o2 sensor and verified the voltage going to it
Changed the timing from 12 degrees btdc to 14 degrees ... runs much better
Continued with lucid's suggestions of plugging the ignition module
Plugged the vacuum line going to the FPR according to suggestions
Ran 2 cans of gas treatment through it (conklin products that are mostly methanol)"

So it seems that plugging the FPR along with timing advance, and gas treatment all preceded the "re-test" with worse readings. So I'm confused about what was done when in the testing sequence.

At any rate, I'm suspicious of the FPR plugging. It may work to mask or compensate for vacuum leaks, but it's a "new idea" here and has never been reported as a high NO fix in the 4+ years that I've been reviewing the subject on this forum—unlike the repeated successes with the ICM vacuum plugging. I don't think that raising the fuel pressure on a hunch is the way to go here.
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Bruce Young
'93 940-NA (current), 240s (one V8), 140s, 122s, since '63.