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Old 12-14-2013, 06:57 PM   #335
jamesm
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Join Date: Mar 2013
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Quote:
Originally Posted by ztan View Post
Thanks Td-d.
Interested in the direct v. port info because:
Looking at injector scaling, I did the following:
Engine up to temp
ECU reset (stock ROM except IAM=1.0)
Started up and logged idle at 20Hz
Discarded initial data with fueling status 1 (OL not up to temp) and logged with no accelerator input.
Divided data into
first half (IPW1>0) - I assume this means port injection on. Mean STFT+LTFT = -7.16%
second half (IPW1=0) - I assume this means port injection off. Mean STFT+LTFT = +2.14%
I'm not sure what controls the injection switch over with other parameters all logging similarly.

I can imagine that fueling control may be difficult if each set of injectors is skewed in different directions, especially at breakpoints where port/direct fractions switch.
i saw the same thing tuning my car for e85. i would log fueling error with the ports turned off and get corrections in one direction, then log with ports only and get different results. getting both 'in spec' independently fixed virtually every drivability problem i had prior to doing this, particularly rough idle, rpms hunting, dipping rpms coming to a stop, stumbling at tip-in, etc. all related to big swings in afr introduced by the disparity in required trim when the switchover happens between injection modes.

you can use the 3 port/di ratio tables to set the ratio. 100% is port only, 0% is di only.
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The Following 2 Users Say Thank You to jamesm For This Useful Post:
mad_sb (12-18-2013), ztan (12-14-2013)