lean after startup first 5 minutes
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From: Lufkin TX/ Baytown,TX
lean after startup first 5 minutes ok im having issues now to my afr being really lean after first startup( cold, warm, all first startups) but it runs great after around 5 minutes and my afr comes back to my commanded afr
ive added 10% to after start enrichment and it still is lean
ive also used the vcm scanner to command lower afr and it still shows to be lean
my question is what do i need to adjust to get this thing from being lean?
it will backfire if i drive it right after starting it but after 5 minutes everything is spot on
mods are
ls1
afr 205
230/234
fast 92/90
30# SVO redtop
bolt ons
thanks for any input
ive added 10% to after start enrichment and it still is lean
ive also used the vcm scanner to command lower afr and it still shows to be lean
my question is what do i need to adjust to get this thing from being lean?
it will backfire if i drive it right after starting it but after 5 minutes everything is spot on
mods are
ls1
afr 205
230/234
fast 92/90
30# SVO redtop
bolt ons
thanks for any input
Last edited by edub80; Sep 9, 2012 at 09:52 PM.
Well warm start it should not last that long I would not think. Sounds like a start up table of some sort. I would think one of the ect based tables, but if it does it on warm start too that kinda rules that out.
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From: Lufkin TX/ Baytown,TX
Well on warm starts its less time maybe like 3 minutes or so... I've messed with the open loop eq ratio too but nothing i do changes the lean condition... i mean im really stumped on this.... everything else in my tune is spot on except this problem
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Thread Starter
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From: Lufkin TX/ Baytown,TX
Jimmy- 1.lean as in 15.7 on scanner... isnt the afr supposed to be around mid 13s in your warmup after a startup?
2 air is not active
98camarod- it does it at cold startups....it does it on every startup at every temp .... i could understand if it was at high iat temps only but It's not
2 air is not active
98camarod- it does it at cold startups....it does it on every startup at every temp .... i could understand if it was at high iat temps only but It's not
If you mean scanner, looking at the narrowband O2 sensors,
those are dead unreliable when cold. I'd assume that
singe you're giving AFR digits this is a wideband meter
that's feeding the scan tool?
There is an air mass calculation that uses ECT and IAT
(charge temp bias), and these readings (esp. ECT) do
lag the reality somewhat. If it stabilizes AFR at the same
time ECT stabilizes, maybe this is it. The open loop EQ
vs ECT may need to be gamed some if being lean is a
real problem. The stock bias between IAT/ECT may be
inappropriate if you change the intake plumbing much.
You might experiment with extremes of the bias setting
(all-IAT, all-ECT) and note the effects relative to the
stock settings, and apply some windage at the lower
airflows.
those are dead unreliable when cold. I'd assume that
singe you're giving AFR digits this is a wideband meter
that's feeding the scan tool?
There is an air mass calculation that uses ECT and IAT
(charge temp bias), and these readings (esp. ECT) do
lag the reality somewhat. If it stabilizes AFR at the same
time ECT stabilizes, maybe this is it. The open loop EQ
vs ECT may need to be gamed some if being lean is a
real problem. The stock bias between IAT/ECT may be
inappropriate if you change the intake plumbing much.
You might experiment with extremes of the bias setting
(all-IAT, all-ECT) and note the effects relative to the
stock settings, and apply some windage at the lower
airflows.
Thread Starter
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From: Lufkin TX/ Baytown,TX
If you mean scanner, looking at the narrowband O2 sensors,
those are dead unreliable when cold. I'd assume that
singe you're giving AFR digits this is a wideband meter
that's feeding the scan tool?
There is an air mass calculation that uses ECT and IAT
(charge temp bias), and these readings (esp. ECT) do
lag the reality somewhat. If it stabilizes AFR at the same
time ECT stabilizes, maybe this is it. The open loop EQ
vs ECT may need to be gamed some if being lean is a
real problem. The stock bias between IAT/ECT may be
inappropriate if you change the intake plumbing much.
You might experiment with extremes of the bias setting
(all-IAT, all-ECT) and note the effects relative to the
stock settings, and apply some windage at the lower
airflows.
those are dead unreliable when cold. I'd assume that
singe you're giving AFR digits this is a wideband meter
that's feeding the scan tool?
There is an air mass calculation that uses ECT and IAT
(charge temp bias), and these readings (esp. ECT) do
lag the reality somewhat. If it stabilizes AFR at the same
time ECT stabilizes, maybe this is it. The open loop EQ
vs ECT may need to be gamed some if being lean is a
real problem. The stock bias between IAT/ECT may be
inappropriate if you change the intake plumbing much.
You might experiment with extremes of the bias setting
(all-IAT, all-ECT) and note the effects relative to the
stock settings, and apply some windage at the lower
airflows.
and your second paragraph is
to me lol...... ive played with the open loop eq vs ECT and it did not show any results.... Thread Starter
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From: Lufkin TX/ Baytown,TX
Thread Starter
11 Second Club
iTrader: (2)
Joined: Feb 2011
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From: Lufkin TX/ Baytown,TX
im running an 85mm maf... im not running an olsd tune... do you still think i should disable the STFT's?? ive searched all over this site and the hptuner forum and i have yet to see anybody run without the STFT enabled
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From: Lufkin TX/ Baytown,TX
ok so im commanding a low afr in open loop FA vs ECT vs MAP and my wideband is showing 15.74 as soon as i start it up....... what tables can i adjust to get it to run richer at startup....... ive added to afterstart enrichment up to 20% and it does not help at all...
i dont mind it being lean at startup idle its just its so lean that its backfiring out the exhaust and has bad hesitation..... i know it needs some fuel but i cant get it in there
OR could the wideband be giving a false lean reading at idle? could it possibly be pig rich and not show on the wideband at idle? i havent tried cutting fuel out
i dont mind it being lean at startup idle its just its so lean that its backfiring out the exhaust and has bad hesitation..... i know it needs some fuel but i cant get it in there
OR could the wideband be giving a false lean reading at idle? could it possibly be pig rich and not show on the wideband at idle? i havent tried cutting fuel out