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View Full Version : Another AutoVe question....?



67SS509
May 24th, 2007, 01:33 PM
If I want to tuneup my Ve table with AutoVetune and then return the pcm to normal operation (closed loop with the maf), do I need to do it in open loop with the maf in operation or in open loop speed density?

I have searched but could not find the answer for this also. Can I set the the maf freq. fail to 0 and leave it plugged in to retain the IAT sensor? What about fail limit...0 or 1?

SSpdDmon
May 24th, 2007, 03:43 PM
speed density = no maf and fueling is done using the VE as the foundation
open loop = pcm commands afr, nbo2's are ignored, and fuel trims are not used
closed loop = pcm commands stoich AFR, stft's are on at a minumum, and pcm is making adjustments based on nbo2 feedback.

Don't confuse speed density with closed or open loop. They're apples and oranges.


If you're not in speed density, that means the MAF is active and the VE is blended with the MAF until the MAF takes over completely, which happens at 4,000rpm with the factory settings. The theory is to get the VE right and then re-enable the MAF to adjust assuming the VE is still right. You want to do both in open loop.