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Idle drops very low. Bad tune?

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Old Dec 30, 2016, 05:35 PM
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Originally Posted by Evo47
I think it's a bad tune. Timing advance goes up to 46 wot, and i got 4 counts of knock at one point. Tps is always at 15 when off trottle, shouldnt it be at 0? AFR is at 14.7 on idle. What else should i be looking at during the log?
No it should not be 0.

it should be 14.5-15.5 fully closed at idle.
If the reading is above 16 the ecu no longer is at ''IDLE".
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Old Dec 30, 2016, 05:39 PM
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Originally Posted by 4b11slayer
No it should not be 0.

it should be 14.5-15.5 fully closed at idle.
If the reading is above 16 the ecu no longer is at ''IDLE".
hmm, checked the log again and the tps is not always the same at idle. goes anywhere from 14.9 to 16.07.
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Old Dec 30, 2016, 05:44 PM
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Originally Posted by Evo47
hmm, checked the log again and the tps is not always the same at idle. goes anywhere from 14.9 to 16.07.
Did you do a boost leak test?
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Old Dec 30, 2016, 05:47 PM
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Originally Posted by 4b11slayer
Did you do a boost leak test?
Originally Posted by Evo47
Update. Did the boost leak test. Large leak in the tb gasket and a small leak in the piping (clamp not tight enough), also 2 of the hoses behind the intake manifold were completely off. fixed both things but still seeing the same thing. Car does feel slightly smoother and It feels like I got 30+ HP back, but still feeling that rough idle. My car died on almost every stop sign, no change when it got warmed up.

Another Update. CEL popped up, P0446, something to do with EVAP. Tried doing a log while stationary, car died every time after i gave it a rev past 4-5k rpms.
Yep, second to last post on the 1st page of this thread.
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Old Dec 30, 2016, 05:48 PM
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Just read your post about the car setting a p0446. If the purge control valve is stuck open, you can be sucking in unmetered hydrocarbons from the charcoal canister and gas tank.
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Old Dec 30, 2016, 05:49 PM
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Oh also no one asked what your afrs are when this happens?

Do you have a Wide band 02?
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Old Dec 30, 2016, 06:01 PM
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Originally Posted by 4b11slayer
Oh also no one asked what your afrs are when this happens?

Do you have a Wide band 02?
I don't have a wideband, on the log the afr's are usually at 14.7 at idle. sometimes it leans out to 15.68.
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Old Dec 30, 2016, 06:19 PM
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Originally Posted by Evo47
I don't have a wideband, on the log the afr's are usually at 14.7 at idle. sometimes it leans out to 15.68.
I don't think that equals to wide band readings
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Old Dec 30, 2016, 08:53 PM
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Originally Posted by 4b11slayer
I don't think that equals to wide band readings
Where can i find the purge control valve? And as for afr's, when i did the log they would always change, wot they go as low as 10.3. Seems accurate to me.
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Old Dec 31, 2016, 11:30 PM
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Originally Posted by Evo47
I think it's a bad tune. Timing advance goes up to 46 wot, and i got 4 counts of knock at one point. Tps is always at 15 when off trottle, shouldnt it be at 0? AFR is at 14.7 on idle. What else should i be looking at during the log?
Your TPS is right, 14.7-15.3 is good idle. The timing advance of 46 sounds absolutely nuts and incorrect though. Do you want to upload a log of maybe a couple third gear pulls? Log RPM, Throttle Position, AFR, LTFT, STFT, 2 Byte Load, Knock, and Timing Advance as well as Injector Pulse Width. Log for a couple minutes at idle too. I'd be happy to take a look at the logs and your tune if you'd like. Only have experience tuning 4-6's though in the Evo family as we don't really have many 7-9s in Canada yet. Shouldn't really be much different unless you're in a IX with MIVEC. Also if you're running E85/etc it may be better I don't help. We don't really have it at all where I live so all the cars I've tuned for friends/myself/customers have been on pump gas.

If you're hitting 10.3 afr at WOT on pump gas you are running ridiculously rich.
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Old Jan 1, 2017, 10:46 AM
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Originally Posted by Ferp
Your TPS is right, 14.7-15.3 is good idle. The timing advance of 46 sounds absolutely nuts and incorrect though. Do you want to upload a log of maybe a couple third gear pulls? Log RPM, Throttle Position, AFR, LTFT, STFT, 2 Byte Load, Knock, and Timing Advance as well as Injector Pulse Width. Log for a couple minutes at idle too. I'd be happy to take a look at the logs and your tune if you'd like. Only have experience tuning 4-6's though in the Evo family as we don't really have many 7-9s in Canada yet. Shouldn't really be much different unless you're in a IX with MIVEC. Also if you're running E85/etc it may be better I don't help. We don't really have it at all where I live so all the cars I've tuned for friends/myself/customers have been on pump gas.

If you're hitting 10.3 afr at WOT on pump gas you are running ridiculously rich.
​​​​​​That would be awesome. I really needed someone to talk to about tunes. I spent hours watching all the tutorials on YouTube and reading all the guides here on forums but I'm still very cautious about doing anything to it myself. I'll try to log at least 2 pulls today. Might be kind of hard to find a good place to do that since there are cops at every corner today haha. I recently did have have a tuner look an older log and ecuflash file and he also told me my numbers were way off.
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Old Jan 3, 2017, 06:43 AM
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Another possibility is the IACV (idle air controller valve) .. id make sure your set screw is set properly too.. might need more air.. see if you can adjust it and get it to idle at around 1k rpm
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