Fred SS

iTrader: (3)

I have mass air, flat tappet, aluminum head 350TPI in my 87 Monte Carlo SS. I'm running the ARAP bin, that I have tweaked and continue to tweak as I learn more about tuning. It's a blast to drive and cruise. Lots of low end torque. Anyway, while going thru the bin, I have seen parameters for DFCO. What is DFCO? and how does it affect driveability?

Tuned Performance

iTrader: (92)

DECELERATION FUEL CUT-OFF
During conditions of extreme deceleration, such as what would happen if you let off the gas when the vehicle is traveling at highway speeds, a complete fuel cut-off of the engine can be commanded by the ECM to cut all emissions output. This also has the benefits of allowing the engine’s compression to slow down the vehicle (called engine compression braking). The ECM looks at MAP or MAF, TP, and vehicle speed to determine when to enter decel fuel cut-off mode and how long to stay in this mode. This mode overrides decel leanout mode. Instructions in the ECM programming determine when this mode is to be exited to prevent engine stalling.

Fred SS

iTrader: (3)

Thanks Tuned Performance. Very informative reply. I will not be messing with DFCO unless I think there is a problem, which I don't have (knock on wood).

Vader

Fred - Don't overlook the forum for tuning: https://www.thirdgen.org/forums/diy-prom/

Fred SS

iTrader: (3)

Thanks Vader, I should have posted in that forum. I wasn't thinking.

Vader

That's O.K. - I just put that up as a reminder to all the help you can get there as you refine the tune for your setup.