My GTO along with a couple more, have had these huge spark dips upon light decel or when the clutch is pushed in. The problem I have is that whenever this happens my AFR is going way lean and skewing my data collected.

Any ideas what is causing this? Anyway to keep AFR stable or constant at these spots? I attached the tune and log files.

Thanks in advance...

Here's a snapshot of the dips which can be found throughout the log.

 

^^^ BTW I have my CFCO and DFCO ECT and RPM enable Parameter set to MAX values.

 

There is also a table that cuts fuel when you press the clutch. I'll have to look and find the name of it.

EDIT: The table is "DFCO enable Clutch transition" in HP tuners. Right under the DFCO area

 

I believe there are also spark tables that adjust spark
based on commanded AFR (EQ ratio) and maybe the
fuel cut is driving the spark pullout via that.

 

That looks somewhat similar to what mine has been doing. It's something to do with the clutch being in. It seems kinda better after playing with the throttle follower tables but I don't think thats what was causing it.

 

Something with the clutch for sure.

 

After eliminating possibilities... I came to the conclusion that this has nothing to do with the clutch or DFCO...

The Advance dips all the way down whenever I let go of the gas completly... or when ETC is <3%.

Is there anyway to tune this out? I hate the fact that my AFR goes way lean during these conditions. I'm currently running OLSD.

 

Wait, the LS1 PCM pulls fuel when you press the clutch in? What if I have my foot on the throttle while it tries to pull the fuel when I shift?

Does this aid at all in smoothness(or lack of notchiness) when shifting?

 

Since I have no idea what setup you have I'll throw out a few things.

Since the lean condition is there I'm thinking it's the minimum injector cycle.On Vette's is it very common when you put in larger injectors for this to happen.You just lower the minimum injector pulse cutoff which ussually gets rid of this problem.