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      12-15-2017, 01:40 PM   #23
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So switching between the stock map and my bootmod3 maps (OTS and Custom), I can say that the engine almost dying issue does not happen with the bootmod3 maps. The odd idle seems to happen only after a cold start and if I don't move the car just leave it idling (with the bootmod3 maps, stock still does what I mentioned previously), but goes away once driving. It may do it after warmed up very slightly, but I think this "issue" is normal amongst catless cars, I must be picky haha.
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      12-15-2017, 02:44 PM   #24
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Pay to play, I have a pretty good understanding of modern obd2 engines and what can cause what....in open loop meaning 02s not warmed up yet and the cars running off a set algorhythm the 02s reading isnt part of its high...closed loop (the opposite) so much flows though the 02 it either cuts fuel to compensate for reallly what is esentially a slightly more efiecient motor so it cuts fuel or idle valve or something causing a dip before correction...proper tune will fix this improper wont...

Also turbo cars get all the back pressure they need from a small turbo...However less back pressure after turbo COULD cause boost spikes, lean, or overboost conditions if not adressed
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      12-15-2017, 02:50 PM   #25
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Quote:
Originally Posted by DKM2Power View Post
Pay to play, I have a pretty good understanding of modern obd2 engines and what can cause what....in open loop meaning 02s not warmed up yet and the cars running off a set algorhythm the 02s reading isnt part of its high...closed loop (the opposite) so much flows though the 02 it either cuts fuel to compensate for reallly what is esentially a slightly more efiecient motor so it cuts fuel or idle valve or something causing a dip before correction...proper tune will fix this improper wont...

Also turbo cars get all the back pressure they need from a small turbo...However less back pressure after turbo COULD cause boost spikes, lean, or overboost conditions if not adressed
Yeah makes sense thanks! For our cars doesnít the MAF play a role in idle too? At WOT itís speed density/closed loop?

Thanks.
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      12-17-2017, 09:22 PM   #26
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Quote:
Originally Posted by inline6ax View Post
Yeah makes sense thanks! For our cars doesnít the MAF play a role in idle too? At WOT itís speed density/closed loop?

Thanks.
TBH BMW is so comlicated but ur prob spot on....most cars are in open loop at WOT bc how could they use an 02 reading that is "behind the egine" In other words by the time thr DME gets the lambda the cars at a completely diff AFR...

BMW uses MAP TMAP IAT etc...may use 02 to adjust long term trims?
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