Anyone solve this mystery?
The MAP values universally increased by ~10kPa+, it did not become erratic. The motor started running rich all the way home. Prior to this point the AFR was in the mid 14's as you can see from the attached .jpg. The car started up again on the key twist once I got it home and it idled at the proscribed 8-900rpm. Didn't measure what the MAP value was but the WB AFR was reading 13.5 or so. Maybe its just something that re-sets itself.
Very odd. I think I have encountered this once before. I was driving around for a tuning scan, and the BLM's were looking pretty good. And then they just dropped without any change to the rpms or driving surface or anything. I was running along the sidestreets in our development.
I've attached a .jpg of the scan at the moment this happened. You can see that the MAP value (shown as User 1) here just increases while the AFR at the top starts to drop right after that. And the MAP value stays fairly constant after the increase.
The numbers to the right of the graphs represent the value at the scan position for the perpendicular line.







