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View Full Version : Why does AFR go real rich on the 1-2 shift?



LS1_Dragster
September 15th, 2009, 02:52 PM
97 Yukon with the 0411 computer upgrade and 02020003 OS.

When it shifts into 2nd the AFR goes to 11.25 (commanded is 12.75) then slower approaches the commanded AFR after 3.5 seconds, does this at +70% part throttle and at WOT.

Not sure if it does it on the 2-3 shift since there's no room to test it....

Lee

SSpdDmon
September 15th, 2009, 02:55 PM
PE step size too small?

LS1_Dragster
September 15th, 2009, 03:08 PM
Sorry, I needed to give more details:

I'm running Speed Density mode, I'm not sure if that applies?

I'm using B3647 to command the AFR instead of PE.

B3618 is all set to 14.68.

BTW, I looked at a log last week on a freeway run and it did it also on the 2-3 shift.