Anyone else notice that when the motor is in DFCO it feels like it's going to shake apart? Any reason for this feature other than fuel economy?
Anyone else notice that when the motor is in DFCO it feels like it's going to shake apart? Any reason for this feature other than fuel economy?
I think you mean AFM/DoD.Originally Posted by Harlech
DFCO doesn't feel like anything.
No, you can clearly feel when it goes into DFCO, watch your wideband and when it spikes lean it feels like the engine is vibrating. You can be off load and coasting and be fine but soon as it goes into DFCO the vibration comes back.
I haven't had AFM on this truck since an hour after it rolled off the lot, Higgs.
decal fuel cut-off mode (dfco)
Fuel Cutoff Mode
The ECM cuts OFF fuel from the fuel injectors when the following conditions are met in order to protect the powertrain from damage and improve driveability:
The ignition is OFF. This prevents engine run-on.
The ignition is ON but there is no ignition reference signal. This prevents flooding or backfiring.
The engine speed is too high, above red line.
The vehicle speed is too high, above rated tire speed.
During an extended, high speed, closed throttle coast down—This reduces emissions and increases engine braking.
During extended deceleration, in order to prevent damage to the catalytic converters
Deceleration Mode
When the driver releases the accelerator pedal, air flow into the engine is reduced. The ECM monitors the corresponding changes in throttle position, MAF, and MAP. The ECM shuts OFF fuel completely if the deceleration is very rapid, or for long periods, such as long, closed-throttle coast-down. The fuel shuts OFF in order to prevent damage to the catalytic converters.
got any dtcs? I don't know if any of that info helps
Last edited by ls-tech; 01-05-2019 at 11:49 AM.
i haven't felt anything like that on a few hundred GM vehicles with DFCO. Even my whipple/cam z06 is goes in and out of dfco smoothly and quickly and is imperceptible while fuel is shut off.
It's barely perceptible, but it's there, I can hook the EVA up to it and grab the frequency. But it's definitely tied to DFCO. Think I'll just disable it, don't see any reason to leave it on at this point.
I glade I read this. I'm always concerned after a hard pull that when I let off my wide band goes to max lean. If I tap the throttle is corrects. I thought air leak in down tube. or worst something broken. I was going to ask how to delete/disable it but sounds like it is a good thing.
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