project_skyline

iTrader: (30)

Alright so I've held off a while on trying to get help on this but its getting really annoying and possibly causing some newer issues.

Mods:
Hks 272's
HKS cam gears 0/0 i believe
TBE
2.5in IC pipes
3.5in IC
ETS intake
Hallman MBC
APS bov - recirculating
ACT xtreme 6 puck sprung
Stock ecu- tuned by me
73k miles on everything

Let me put a brief history out on the car. I bought it last year in august, the car had a apexi power FC, i had it tuned locally. It didn't have any issues idling like stock.

In january i switched to AEM EMS and worked on street tuning it. No matter what I i did with timing or fueling i noticed it had developed a idle issue. It seemed like it has giant loppy cams in it and while sitting still sometimes if I reved it they would hang at 1500 and then drop down again to 1k.

March I sold the AEM because I didn't have any use for it from being laid off and went back to the stock ECU. Again after tuning it the idling issue was still there. It also seems to have a hard time sometimes with the idle catching and it bogs down to 500rpm's or seems to idle there unless i prod the gas to bring it back to 1000. Now because I have changed many variables in the tune on both the AEM and stock ecu im looking towards another possibility such as a sensor or something below. But im not sure what it might be.

Things i've done so far whether related or not...
Compression test (within spec)
Boost/vaccum leak test (throttle shaft seals[getting replaced])
cleaned the MAF
a few months ago pulled the IAC motor off and inspected and cleaned it
changed plugs
Checked EGR, had vaccum lines off but that was recent.

Any ideas or suggestions would be highly appreciated!
Thanks

rolly1818

injectors scaled correctly?

fuel trims in order with new intake?

project_skyline

iTrader: (30)

Well im not in closed loop anymore but back when I was scaling everything I got fuel trims on low and mid to within 4%.

Everything including MAF is now scaled very well at least from what its showing me.

BerserkerX

Usually its the smallest thing that can cause the biggest issue. I had issues with idle on my talon because of an oxygen sensor and a failing tps. Does it idle like that whether its cold or warm?

EvoVIII808

iTrader: (4)

I also had a problem like this. My EGR was lose, and was letting the air out, Also check Vac. lines.
Just a stat to get you in the right direction.

JakeTheVIII

iTrader: (35)

I've always had idle problems switching intakes, especially smaller ones. Sounds like you've tried just about everything, mess with the biss screw?

rolly1818

not to sound ignorant, but from what i read they always say dont touch the BISS screw? (i dont have much knowledge here).

when ur getting this bad idle does the car idle lean or rich?

project_skyline

iTrader: (30)

It does it warm or cold but its only noticeable when its under 1200 rpm's.

I have tried adjusting the BISS but it didn't help.

I will check the EGR soon, i have the block off plate to throw on it anyway.

From what my wideband tells me its lean but its also only on the tail pipe. On the aem it was in the exhaust and I remember that no matter what I changed the fuel to that it showed lean as well.

I totally forgot to mention that.

BerserkerX

According to my limited knowledge from reading the books that I have you might want to run in rich. Rich idles better and controls it. Ha ha you could be lazy and be like my friend and take the easy way out when he switched cams, he just raised idle to like 1300. Check your oxygen sensor to see if its throwing the right voltage. if i remember its between 0-1.

But check your egr too. also you dont have an exhaust leak do you? if exhaust goes into your maf it wont idle right either. what about your tps? my sentra had an issue with that and the plenum leaking. But you said you checked that. Gl with it man.

1sxyrxy

iTrader: (10)

pull vacuum port off of the EGR, apply vacuum to it and see if it makes the stumble even more. if it still idles like crap then its a faulty EGR

project_skyline

iTrader: (30)

Like i said even richening the crap outta of it on the fuel maps it still generally shows lean.

Also since the 02 sensor doesn't control anything right now since I run full time close loop I dont suspect it.

I had an exhaust leak but i fixed that.

I'll check that too when i get the chance.

project_skyline

iTrader: (30)

bump i checked everything and still no change.

Could this possibly be caused by some sort of failing sensor other then EGR?

project_skyline

iTrader: (30)

common this is evom, where is the help lol.

jhanksevo

iTrader: (44)

to be honest i had a horrible idle recently and i checked everything and still couldnt find out why my idle just wasnt right. I was running a jdm 9 bov then I switched back to my forge rs and no problems. B4 the switch I was running super rich at idle the car acted like it wanted to die if I didnt give it gas and i kept throwing a p0172 code. After the switch that all changed.

Hope this helps