MSefi.com read only forum (Jan.15,2018)

I am haveing a problem with the afr going very lean while driving. I have the EGO correction off and am trying to tune. What happens is that the motor will start running rough and cutting out. The afr goes very lean and I see that the PW goes up a lot. I was looking at a datalog and saw that when the afr goes really lean and the PW goes up there is a drop off on the IAC counts from the 250 that I should have at running temp to 150. I think that this is causing the lean condition and the PW goes up to try to compensate for the beg jump in the MAP reading. What would cause the IAC to make this jump and then correct itself?

Look around 1485.

Also there seem to be some strange spikes in the VBAT. Thanks. Billk

I can't load the datalog because it is too large. Is there a way to cut back the datalog size by chopping off some of the early or late parts? Billk

Strangely, I have not seen the problem again. ??? Billk