fuel cut tips
Moderator: Gaskleppie
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- Posts: 7
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- Location: USA
If I was to guess why MBAR jumps, it's due to less scavenging during overlap. With the cyl pressure at practically zero due to no combustion, there is no exhaust scavenging, and less air is drawn into the cylinder during overlap - so more air/pressure is left in the intake manifold. This could very well be another reason why tuner versions don't see this as much, as they may tune w/large overlap cams which don't have as much scavenging at such a low mbar/rpm. I haven't seen the options for a long time, is there \"hysteresis\" in the code for pressure? It seems like it's needed for a lower cut and higher reactiviation to deal with that rise in mbar after fuelcut.
update: From my last post my car has changed alot; updates in the software, I replaced every seal and gasket in the IM to include that stupid screen in the IACV, Larger injectors, 4 bar map, turbo... After all of this I can say that fuel cut works fine now. I am not sure exactly what combination of the above fixed it, but I do know that I was having major issues with the FITV and after I cleaned it and put new seals in it, everything has worked perfect. I had a small issue at very light throttle with the car bucking in and out of fuel cut but I fixed this by changing the TPS% lower. So no problems at all with this so far.