Also some recent info for those who need to keep to emissions standards.
A high vac idle with low rpm speed is good for economy, but not necessarily emissions. A higher idle speed and less advance keeps things hotter and heats the cats better due to faster airflow and heat into them. This may be especially important with aftermarket headers and cats back from stock location where they take longer to heat up and therefore dont work properly.
Im helping a fellow owner try and pass emissions. The local emissions place lets us play on their gear for next to free as they are interested in the cars too. Cool. I think we might have an issue as they have 100 cell cats and aftermarket headers etc.
We can zero out HC and CO but only by breaking the lambda limit. If we stay at the top end we get too much CO. I think we/he might need to wrap the headers or upgrade the cats.
Ill start another thread where this is more relevant later with the final results.