Thread: Cruisin
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Old Sun, February 28th, 2010, 09:47 AM
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cleatus12r cleatus12r is offline
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HA HA!

A few things that have effect on the jerky, on/off cruise control......
  • PW multiplier with too much "spread" between ICP ranges (y-axis)
  • Low boost fuel. Again, not gradual enough.
  • MFD/Inferred relationship. If the range in which you're "cruising" happens to fall into an area where the MFD is high/low (like a non-linear APP) where there is virtually nothing for the first 1/4" of pedal travel, all of a sudden it shoots off like a rocket, then tapers off past half way, there can be issues. This is made worse when the inferred throttle position is trying to control the MFD through this "touchy" pedal.

I hope this helps a bit and makes a little bit of sense. I am combining the jerking/sputtering while going down hills and the on/off cruise control. The worst was my previous tuner's programs while going up and down little rolling hills (10 or so feet of elevation change about 200 yards apart. My brother ran some programming that caused everyone in the truck to "head bang" at a frequency of about 3 Hz when driving down some of these 6-7% grades around here with the cruise control on.

Believe it or not, the manual transmission MFD map (that I sent you) took care of a lot of issues without any other changes.
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Tuning, PCM flashing, burning chips, and repairing all aspects of 7.3L Powerstrokes.
Eight 7.3L PSDs in the driveway including a 1994 Crown Vic and 1973 F100/2002 F350. Looking for the next victim.
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