Lean idle when warm, checked basics

[waxball88]

I have the same issue man. I'm KA-T though. Idles fine on first start up/after sitting. Once its warmed up/start driving most often boosting and i come to a stop it will slowly lean out til max, then starts with the shitty idle. Or it will try and stumble, sometimes die if i dont blip the throttle.
Other times it will sit and idle like a fucking champ.
After i boost leak tested/fixed my car, response was better but the lean issue was more pronounced. Hesitation on tip-in throttle, runs fine if i'm dogging it (although rich) which implies boost/vac leaks.
I'm about to go back outside and replace more lines and see if anything can rid me of this forsaken problem.

[rps_jrdn]

Originally Posted by KiLLeR2001

I'm starting to think something with the tune at this point.

i agree.... 9.5 10.8 is quite rich when boost hits.... should be at 11.6-12.1... i'm surprised your not shooting black smoke out the tail pipe from running that rich on full boost.

perhaps it maybe the idle air control valve too thats causing the lean idle...

[KiLLeR2001]

Try another MAF that is known to be working correctly... But before that check the MAF wiring ALL the way through. Make sure the signal wire is shielded so theres no interference.

[di-devol]

Originally Posted by rps_jrdn

i agree.... 9.5 10.8 is quite rich when boost hits.... should be at 11.6-12.1... i'm surprised your not shooting black smoke out the tail pipe from running that rich on full boost.
perhaps it maybe the idle air control valve too thats causing the lean idle...

I'm struggling to think it's the tune, I figured if it was the tune it would NOT be intermittent, ya know?
lol, I try to look for smoke but there is always too much tire smoke. I can't hook up at full boost. I unplugged the IACV, idle just became more rough. The idle screw on the IACV works correctly as well.

Originally Posted by KiLLeR2001

Try another MAF that is known to be working correctly... But before that check the MAF wiring ALL the way through. Make sure the signal wire is shielded so theres no interference.

I am going to try a known working MAF on Thursday, I can trace wires when I get home tonight.

Thanks guys!

[ultimateirving]

did u completely reset your innovate unit when installing the new sensor. read the manual from innovate and make sure to completely reset the unit.

[towlie]

I may have missed it, what exactly are your afr readings at idle?

Did you try calling jwt and explaining your situation? Maybe they could give you some pointers

[di-devol]

Originally Posted by ultimateirving

did u completely reset your innovate unit when installing the new sensor. read the manual from innovate and make sure to completely reset the unit.

Yup, but I can try it again just to be sure.

Originally Posted by towlie

I may have missed it, what exactly are your afr readings at idle?

Did you try calling jwt and explaining your situation? Maybe they could give you some pointers

Watch the videos man. 22.1afr

I've been in contact with JWT, being intermittent, it something with my set-up.

[towlie]

Yeah, what the fuck?

Try that MAF and see what happens. I have a brand new stack w/b we can hook up to make sure your innovate is working correctly if u need to. I'm lost otherwise lol

[di-devol]

That would be awesome if it comes to that man lol.

[towlie]

No problem u have my number. I just got it wired up today, My car idles at a 13.9-14.1 @ 850 so it's dead on

[di-devol]

Alright, I re-wired the maf last night, and for the hell of it I re-wired the injectors. I went for a drive to the airport to pick up my wife. Big difference!

No hesitation on light throttle whatsoever, but boost was 7-8 afr lol. I replaced the new bosch sensor with another, did a sensor calibration, heater calibration and cleared the settings on the controller.

On the way to work this morning, light throttle is fantastic, boost is 11.2-11.5!!

Still lean at idle, though it's different. Coming to a stop, it runs rich for a sec(open BOV) then idles lean for 1-2 secs(18-19afr) then settle to 14-15 for about 30 sec then climb back up to 17-18, sit there for a bit then lean out off the chart at 21.7. If I blip the throttle, it does the same cycle again. Guessing the IACV for that issue.

Over-all a lot better.

[KiLLeR2001]

Now that you've fixed the wiring try another MAF!!!

[di-devol]

I am!

lol, thanks alot man.

[di-devol]

Tried a different maf, no dice.

[KiLLeR2001]

Redtop SR? Skinny O2 sensor? How does AFR change if you unplug it?

[di-devol]

Red top, skinny O2. Trying that next, unplugging it does not change anything. My JWT tune states O2 feed back is turned on. Always thought that caused a rich condition though?

[KiLLeR2001]

Originally Posted by di-devol

Red top, skinny O2. Trying that next, unplugging it does not change anything. My JWT tune states O2 feed back is turned on. Always thought that caused a rich condition though?

Mostly, but if you unplug it, it should definitely get richer. If nothing changes then it's possible bad O2 wiring or the O2 sensor itself.

[rps_jrdn]

Originally Posted by di-devol

Red top, skinny O2. Trying that next, unplugging it does not change anything. My JWT tune states O2 feed back is turned on. Always thought that caused a rich condition though?

nah O2 feedback on is leaner... O2 feedback off is rich.... there fore unplugging the O2 should make it richer.

[di-devol]

Back from the dead. I could never figure out the lean idle. Car drifted fine, as always it's good in boost. I developed a really bad rich condition in boost over the season though. So I re-did alot of stuff.

Installed a new harness
New o2 sensor
Injectors are not leaking
Maf is good
No boost leak, no vac leak.
Moved the maf out more.
No exhaust leaks.
No change when unplugging the O2 sensor. Wiring checks out though.

Car runs perfect when cold. Well, it runs how it should when it's warm, when cold. Warm up enrichment table makes it run about 14-15 arfs when COLD.

Once warmed up, it leans out to 18-19 afrs. Still runs but makes a lope sound, kinda like a v-8. car is still good in boost.

I've done everything, I'm starting to think it's the JWT tune :/

[codyace]

To have it 'run away' sort to speak is odd, and would be something (IMO) car/harness related that is causing the ECU adjust the fuel. The tune itself isn't going to be setup to just 'keep going lean', something obviously will be telling it to do so.

[waxball88]

Ended up sending my ECU back to Enthalpy, new ecu runs a little rich at idle, no more stalling on decel, or leaning out condition

[codyace]

Originally Posted by waxball88

Ended up sending my ECU back to Enthalpy, new ecu runs a little rich at idle, no more stalling on decel, or leaning out condition

The only reason your car would ever stall on decel is due to unrecirculated BOV. Sounds like the 'fix' is masking an underlying issue.

[di-devol]

It's really weird, cold start is 14-15afr, but idles great at 19-20 vac, once warming up the vac will drop to 15 and lean out. If I try to hold it up at 3k rpms it will drop down to 2k lean out and start to what sounds like a mis-fire.

Yesterday, we tried another o2 sensor, another cts sensor.

I just talked to Ben at JWT, gonna try and move the maf farther away as a test. Also picking up the consult stuff and some software to see what's going on.

[di-devol]

Well i moved the maf ridiculously far away from the turbo with no change. I noticed in boost i started to throw black smoke. Checked the fuel pressure and was around 50psi with no vacuum. Set that back and now no more smoke.

Working on getting a consult cable to use Nissan data scan to see what we can find.

[di-devol]

I've been searching forever on this topic and found numerous people with the same problem one time or another, but never with an answer. So here is an update.

I installed stock ecu, injectors and maf, car ran perfect. cold start was 10ish warming up to 13-14 when warm. Cam sounding lope is gone, I can hold the rpms with good afr's.

Putting the JWT ecu, z32 maf, and the sards back on, car leans out to 21-22 and just stays there. I'm out of stuff to check, and since it ran good on stock stuff, I have to say it's the tune :/

The fuel pressure is odd. With a stock fpr fuel pressure was 50ish, installed a nismo fpr put it down to stock. Now, the car is lean in boost as well at 13-14. So with stock fuel pressure the car is undrivable now.

Just waiting to hear from JWT now.

[waxball88]

Originally Posted by codyace

The only reason your car would ever stall on decel is due to unrecirculated BOV. Sounds like the 'fix' is masking an underlying issue.

It's not impossible, but Martin had me go through his whole bag of tricks before sending it back. I can boost leak to 30 psi and don't hear a peep, all note worth vac lines have been converted to pushlok an. I tried 4 different knock sensors/sub harness combos to no avail. I was running a shitty greddy knock off bov but I tried simply running no bov. I have an apexi bov now, and plans to make it to Martin to have him put his hands on the car in person
Also took apart and cleaned 2 iacvs(told these can cause stalling) Also plan on moving to blow through soon.

[towlie]

Weak, sounds like u narrowed down the problem tho

[di-devol]

I dunno yet. I'm checking everything for the 11th time.

[di-devol]

Updating just for that fact that no one updates.

We had the car tuned on AEM ems, lean issues persisted.

Either the engine hated life, or it was cursed.

Going to blame wiring, bad grounds, something fishy. Motor blew, so end of story.

[towlie]

Looks like you lost then.