Went lean...

Rat Bastid said
The sensor doesn’t lie. It can only measure oxygen content in the exhaust. So it can’t tell the difference between a lean miss and being rich because there is so much unburned fuel left over from the misfire.

That’s what I’m trying to get across for anyone using an O2 sensor. Just because it’s saying something it doesn’t mean that what’s actually happening.

This advice is how the 3 Mile Island accident happened. They didn't believe or trust a gauge reading. I'm not able to be clear, that it went lean. It didn't go lean and misfire and fail to run. It just went lean. Leaner than where I had it tuned. Immediately upon this event. Had I not had an AFR gauge, I probably wouldn't have noticed.

Rat Bastid said
I’m still looking for the other paper by Shrinker. I know I have a copy at home. In it he discusses working with an engine on the dyno and the O2 was saying one thing but the end of it was something else was happening. It s a great paper.

My point is just don’t take the O2 sensor reading as gospel. Look at it and then look at everything else around it and then you make the decision on what’s happening.

And I'm trying to explain to you (but somehow not being clear) that, I DID. The engine performance responded in kind to EXACTLY what the O2 sensor was indicating. Under light light load, the AFR would go up to 20 or maybe even 21. And the engine at low rpm and low load would respond very weak. However when enough vacuum signal was lost due to rpm, the metering rod springs would back out the metering rods, fuel would flow, the AFRs would drop to perfect and the power would come on very healthy. So, I observed what was going on. My AFR gauge was correct, accurate, I believed it and everything else meshed.