1.4T - Lean spikes at throttle close/shifting

[Spcbrn]

Hi there,

I'm in the process of re-scaling the MAF and planned to do SD as well, 1.4T LUJ/LUV engine with an E78 ECM on a car with a manual trans.
I forced it in open loop, DFCO and CFCO turned off.

My problem is that when the throttle goes from wide open to close or when I shift gears, my wideband reads lean and as a result the data I get in the scanner gets messed up
The commanded EQ isn't moving so I don't know if what I see is a normal phenomenon in these situations


If this can't be eliminated, what's the way to get nice data not polluted by these lean spikes? Filtering maybe?
Thanks for the help!

[jmardlin]

Try going into the cutoff,DFCO sub tab in the Fuel tab and set enable rpm to 8000 and disable to 7900. This should essentially turn off deceleration fuel cutoff and get rid of the lean spike. This is a fuel saving feature. When you let off the accelerator pedal they go to minimum injector pulse width till you push the pedal or get below the disable rpm. I have a 2015 manual Cruze with a 1.4l.

[Spcbrn]

DFCO wasn't enabled, as shown in my graph the commanded lambda was fine, I finally got rid of these spikes in my graph by using the filter function.

[2142.156] = 0 AND [2142.156.slope(1000)] = 0 AND [2142.156.slope(-1000)] = 0 AND [50091.156.slope(500)] < 1 AND [50091.156.slope(-500)] < 1

This filters out any data if the clutch pedal is currently depressed or has been depressed in a 2sec window and if there was a significant accelerator pedal movement in a 1sec window

[jmardlin]

I wish there was a master enable/disable for DFCO in my 15 Cruze.

[RoninDusette]

You'll find it even if there is a master enable and disabled for stuff it can still get triggered by other things. So everything that can enable or disable dfco I mean speed RPM engine coolant temperature set them out of specs so that nothing will trigger it. And it'll make it go away. Some things I don't know why they do this that they being the ECU but like you have I don't know and sometimes like your PE won't kick in even though you have it set to zero delay and does that in the other like it should kick in like on mine it just flat out will not go into PE if I set it to zero I tried all the different methods I have to make sure that it has a delay but I give it a delay of one millisecond and have the ramp in come in almost immediately. So that's how I have to get it done on mine otherwise it just will not go into PE. It's just quirky like that. So I mean yours may just be kind of quirky too so try setting your enable speed to 300 mph and then set your enable ECT all the way up set your navel RPM all the way up. I'll bet you'll find it'll go away like much easier. Plus there's a new feature in HB tuners where you can open up your tune make all the changes to disabled dfco that you know work and save that as a template and just call it disabledfco. Then you can just go in there and just apply it like super quick you don't have to go through each one of the tables just boom apply and right. I started using it recently and I actually really love it