I have been reading DCFO, popping, and burble threads for hours and need some input to get rid of decel popping that has at this point destroyed my wideband trying to figure it out.
2009 5.3L aluminum truck block with heads, very mild cam, and LS2 intake, T56 Magnum and E38 that thinks its a 09 Corvette 6.2L for the manual trans speed input. All crammed into a Datsun 280Z
Stock DCFO settings from the base corvette file.
I tuned the MAF and then VVE tables until I was running 0 to 4% rich and overall driving well enough to get on the dyno for final VE and spark tune, no popping or abnormal characteristics while tuning. I Re-enabled O2 sensors, MAF, and DCFO and everything is running great, LTFTs are all low negative BUT lots of popping during decel and engine braking. I was avoiding these conditions as much as possible but making it act up while watching the wideband. Everything was going lean like its supposed to, injector pulse drops to 0.8ms, timing drops close to entry spark settings but heavy popping and burble is present. Didn't take much and after a few times I let it pop my brand new wideband took a crap and I only get spike readings when I make it pop, my guess is it is shocking the element into making temporary connection.
I pulled the wideband and disabled DCFO and 95% of the popping goes away, what remains is a fraction as loud/prominent, you would almost miss it if you weren't looking for it. Looking at before and after logs i can't tell much difference in fueling. Injector pulse still drops to 0.8ms and it goes lean on decel even without DCFO but no popping. Timing advance is where I see the biggest difference and its not a lot.
I can see that many just leave DCFO disabled and while that seems to be working for me it doesn't feel right with the reduced engine braking. I would like to get this working before my new wideband gets here and I make a dyno appointment but before I start messing with entry and exit spark tables would someone take a look and see if they see anything else I'm missing? Currently my entry spark tables are at 10 degrees, would bumping that up to 20 be an unsafe starting point? Would I be better off trying to tune for more engine braking with DCFO disabled?
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