DFCO entry delay

[EC_Tune]

For Deep Decel Cutoff you want it about 20-23 Kpa. You don't want the injectors off unless you are in decel for quite a few seconds.

[stone]

OK I changed it to 23 kPa....25 I didnt have any negative effects but safe = better

[TreyZ28]

Why dont you want it to shut off immediately? what are the draw-backs?

[shimp]

My default injector pulsewidth table looks like this. .851 0-3200rpm then 0.0 all the rest of the tables, attachment is my table.

I don't have a vette or a M6, but my truck is manual trans. I have been debating on what to do about my DFCO pops.

So is my table okay? Can I turn off DFCO? Or should I try changing the settings to make it pop less. I kind of like the extra engine braking provided by DFCO... but I don't like the pops...

[stone]

Actually, I've had DFCO disabled for a week or two now and the ride s much quieter, and it doesnt engine brake like a mofo now....nice After the SD tune I never put the MAF back on and never turned DFCO on...

[shimp]

I like the engine braking... it helps save me from doing a brake job... I'd like to understand the DFCO better so can learn to tune it to my preferences...

[WS6FirebirdTA00]

what do you want to know?

[shimp]

I just want to figure out how to eliminate the pops. Is it a matter of it cutting the fuel too quickly during decel or shift? Is there a way to slow down the process so it doesn't pop? But still take advantage of the engine braking provided by the DFCO.

Also, there are tables in my DFCO that show 6 gears and different RPM's at which the DFCO turns off and resumes fueling. Does my truck (5 speed) know what gear the trans is in or is that only with the M6. It seems like my DFCO always turns off and resumes fueling at 1500 rpms or less.

[EC_Tune]

No it really doesn't know exactly what gear you are in. However it can "do the math" with RPM & MPH to figure it out.

Most of the popping has to do with spark advance and injector cutoff. IIRC, spark is decayed first then fuel is removed. If you decay the spark faster, then the fuel goes off "faster". What you don't want is DFCO that goes on every time you lift a little on the pedal. That tends to make things a bit jerky (engine braking).

Try adjusting the Threshold and Blending values to suit your needs once you find out "where" you want DFCO on.

[alanderson1978]

This seems way too complicated. It would be nice if we had a sticky available that walked you through this.

I'm sort of getting it, but what does DFCO Active Spark do?
I have Spark Advance Table A, and Table A Min TPS, and then both for table B. Stock, Table A min TPS is 100% and Table B min TPS is 99%, which doesn't make sense. Both tables have the same values in them.