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NSW supra club Member
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Discussion Starter #1
hey guys,
i just got my wide band(plx300) and played with it to see what my readings are ect.
what i found, is that my supra likes running around 13:1 afr(runs smoother) on idle, if i bring it to around stoich 14.7:1 afr, it starts hunting/rough idle.
This is on the bkr7e plugs gaped at .8mm

what i would like to find out is, what do you guys run on idle(AFR's) and what plugs are you using with those afr's?
 

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High 13s for my car. Iridium IK27s, 6 motorcycle coils, AEM 8channel AEM CDI. What are you running for engine management? If it's an AEM there are things that can be done to get better idle resolution in the fuel mapping.
 

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Built Auto
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ToMuchBoost said:
Damn man that to lean for a TT supra you should be in 12:1 minimum that reading that you have is for NA supra
if you dont know what you're talking about, stop giving out information.....:rolleyes:

Usually my wideband shows ~ 13-14:1 at idle, using Denso iridium IK22's gapped at .028".

If your idle seems kinda rough at 14:1, have you tried checking for any vacuum leaks? Also what rpm does your car idle at? Optimally you want around stoich afr when idling or cruising.
 

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I have a wide band too you know :rolleyes:
My read out 12.1:1 and on the dyno it's 11:1.
It may be that diiferent types of wideband can show different A/F,but showing 14.7:1 that?
 

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14.7 at idle is the stock AFR. if you have to add fuel to make it idle smooth and you have stock cams then you have a vaccum leak. or your plugs are gaped wrong, its usally a vaccum leak.
 

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ToMuchBoost said:
I have a wide band too you know :rolleyes:
My read out 12.1:1 and on the dyno it's 11:1.
It may be that diiferent types of wideband can show different A/F,but showing 14.7:1 that?
You idle at 11:1 on the dyno and you think this is normal?:p And are arguing about it? As was said, if you don't know what you're talking about butt out. You get what, 4MPG? :lol:

I can maybe go 14.1:1 but a little richer is smoother. Lower ignition timing some and it will help smooth things - obviously those without a standalone need not apply unless you want to fiddle with the intake cam timing.
 

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blackbird said:
14.7 at idle is the stock AFR. if you have to add fuel to make it idle smooth and you have stock cams then you have a vaccum leak. or your plugs are gaped wrong, its usally a vaccum leak.
Stoich is what most think it will idle at but mine has no leaks blah blah and a good ignition system - won't idle that lean. I am MAP based so an idle leak is no big deal for me anyway. I could maybe fiddle injector timing or something but I haven't wanted to work that hard. You running a W/B and seeing a consistant 14.7:1 or did you look that up\assume?
 

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Shawn Davis
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I hate to disagree with some others but mine idles right at 14.7 after warming up (with stock ECU, IK24's, no boost/vacuum leaks).

In fact, I find that the stock ECU attempts to achieve 14.7 (fluctuates 14.5-15.0) at all conditions under ~6 psi boost. So if I have 50% throttle and let the boost keep increasing it sits at about 14.7 until the transition from the first to the second turbo. I was surprised it was this lean at partial boost, but the gauge don't lie (I hope).
 

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I'm at 14.7 too at idle on map but once boost increases you better be richer than that. You won't knock at idle so don't worry.
 

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My car shows 13.8 to 14.1 at idle any leaner it starts to get jumpy.
My Idle is set at 1100 rpms.
I have a Map Ecu and Ik22s.
 

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NSW supra club Member
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Discussion Starter #12
Yeah guys, i am not worried about full WOT, thats not what im concerned about and not my problem(tomuchboost, read my questions properly lol).
I am just trying to see if other people are running richer to smooth out they're idle or if i maybe have a problem.
Mine sort of hunts and a slight poping sound if running stoich on idle, so i tried ~13afr and it ran real nice and smooth.
I am also MAP sensor and a standalone ecu(haltech e11) with stock coils and DLI, and have no vacum leaks.
i will try lowering the timing as suggested by Blkmgk to see what happends and maybe gap the plugs higher(but i would rather not due to high boost).

I just wish i could run it at higher AFR's yet smooth.
 

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Ubermensch said:
I hate to disagree with some others but mine idles right at 14.7 after warming up (with stock ECU, IK24's, no boost/vacuum leaks).

In fact, I find that the stock ECU attempts to achieve 14.7 (fluctuates 14.5-15.0) at all conditions under ~6 psi boost. So if I have 50% throttle and let the boost keep increasing it sits at about 14.7 until the transition from the first to the second turbo. I was surprised it was this lean at partial boost, but the gauge don't lie (I hope).
I agree, at idle on my car (stock ecu, single, stock fuel, FJO) it will fluctuate between 14.5 and 14.8 or so.
 

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These are the AFR'S I run on my 2J

12.2-12.8 at idle
14.7:1 at 25"hg and climbing to ->13:1
13:1 at 0psi
12.5:1 at 1 - 8 psi
12:1-11.5:1 at 8 -20 psi

Anything above 20 psi I run 10.8

Regards,

Andre
 

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mine idles at 15 and sometimes after a long drive itll get to 16... if i blip the throttle itll go to 14 then slowly start going back up to 15 to 15.5... ecu and fuel system is stock
 

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mine idles at 15 and sometimes after a long drive itll get to 16... if i blip the throttle itll go to 14 then slowly start going back up to 15 to 15.5... ecu and fuel system is stock
what is your gas mileage with cruise at those a/f ratio?
 

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Drive Hard
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i read 13,3/13:5 on 272 and aem. it's the best i have done. if i set to 14 the idle became roughtly. NGK 2668 stock gap
 

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i bounce from 14.4 14.6
 
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