Sometimes when I straddle the line between overrun (fuel cut after 2 seconds) and very slight throttle angle (1-3%) at engine speeds above 3000 RPM, I get odd AF numbers. In overrun, naturally it goes to max lean, but then when I barely open the throttle, it’ll go to 11:1 and stay there until I make a change in throttle angle. And gego doesn’t seem to want to pull it back where it should be. In this situation, I achieve vacuum as low as 13kpa.

How does MS calculate a 13kpa condition when the lowest MAP row in the VE table and AFR target table are set to 20kpa? Is there any value to reducing my lowest MAP rows to 10kpa? Just curiously, what would MS calculate if the highest MAP row was set to 200kpa and it was exceeded?

I don’t know if this is a new issue or if I just never noticed it…

 

what you are seeing is accel enrichment

 

you know, i saw the same sort of thing when i was running around in my MS'd '90 until i tweaked around with the map. I think i ended up setting overrun to like 15kpa and used that for the bottom cell of the map

you can manually alter the map under "basic settings" in "fuel VE table" and set the bottom to whatever you want.

 

It takes the final value in that column/row and carries it into infinity (i.e. if you have 7000 as your last cell, and 104% VE at 156kpa and 7000rpm, it will maintain 104% VE beyond 7000rpm.