- Dec 4, 2011
- 568
Just some more notes while playing with HPTuners... I have been trying to adjust deceleration fuel cut-off to work smoothly and help improve gas mileage. The stock settings are crap -- I can't think of any situation where it would actually cut in due to the combination of MAP and RPM settings they use. I found a couple of example tunes for the I6 to start with, but they seem to cause an interesting problem. While decelerating, my engine starts to 'pulse'. The fuel is cut off, RPM will drop to idle, raising my manifold pressure, which causes DFCO to disable, bringing the RPM back up again. At first I thought I had crossed my transmission shift points in some weird way and it was bouncing between gears, but the scanner showed me what was really happening.
So the trick seems to be finding the sweet-spot in the MAP values. I want it to engage when I take my foot off the peddle, but not while I'm just maintaining a steady speed down a hill. Judging by my last run, it looks like enabling at 35 and disabling at 45kPa might do it.
Anyone else messed with DFCO and found some good values?
So the trick seems to be finding the sweet-spot in the MAP values. I want it to engage when I take my foot off the peddle, but not while I'm just maintaining a steady speed down a hill. Judging by my last run, it looks like enabling at 35 and disabling at 45kPa might do it.
Anyone else messed with DFCO and found some good values?