Apexi' NEO tuning/general tuning advice
 

What specifically is your issue with the idle? Do you have a wideband installed? Is the ECU running in a forced, full time open loop mode (I don't recommend it with the Toyota TCCS systems)? Leave the bypass screw on the AFM alone, you don't need to use it in conjunction with the NEO.

Unless the ECU is put into a constant open loop mode (can be accomplished via a few different methods) the ECU will work to adjust the idle AFR on its own just as it does during low to medium load engine operation. This is closed loop mode. The only time you can manually affect the AFR without the ECU fighting you is when it's operating in open loop mode. Open loop mode is engaged when the engine is first warming up, throttle is at 70% or higher (I think it's about 70%), or there is a fault with certain components such as the O2 sensor... These are your tuning windows. Any tuning of the idle AFR will need to be done when the engine is in open loop mode. Tuning should be done to keep the cold idle AFR at about 13:1. Don't try to stray from the ECU's normal operation when it comes to tuning idle, cold operation and closed loop operation... just tune it so the ECU doesn't have to work it's ass off and so the two systems will play nice with each other.

Well that makes a lot of sense! Thanks for clearing that up. How long do you suppose it takes the ECU to learn a new idle when i put the Lex afm in? And the proper reset for the ecu is pulling the ecu fuse from the fuse box under the hood for a minute or so correct?

As for the adjustment screw on the lex afm, what's a good position to put it in? (because it's not where it is stock, I already screwed around with it a while ago and i'm back at it so i don't remember where it was originally)

Thanks!

It doesn't take the ECU long to adjust and learn any offsets as long as everything is already reasonably close to where it should be. The ECU can only adjust things so much, if factors are way off it's not going to get better and just start running well on its own.

Yes, just pull the EFI fuse for 30 seconds or so is all I've ever needed.

As for the bypass screw, It doesn't matter much. You'll be tuning around it with the fuel controller anyway. Just set it close to where you think it was and then worry about tuning with the NEO. The bypass airway screw is essentially just a primitive tuning device.

Now 1 more thing. I'm at it right now and I installed it and reset the ECU and I cannot get it to idle in a safe a/f range. It's off my AEM wideband... What am I doing wrong? I'm going to head out and warm it up so it is using the o2 to adjust idle a/f (correct?) because I think that's the problem, so we'll see how that goes. It's just annoying how many times I've swapped this lex afm in and out since i bought the damn thing. Searching high and low for a step by step installing it but it's all just word of mouth and random tips here and there. Simple thing to do I get that, but I do not want to run lean and do damage, i'm always super paranoid. No clue how some people just toss it in and just drive WITHOUT a wideband! Crazy.

Reset ECU while HOT, figuring it needed to be warmed up to use the o2 to adjust idle, but it did not matter, Idle is still OVER 18a/f. Went out for a drive with fuel pressure at 30 which i believe is too low, it was because i backed it off for the 550cc injectors with no lex maf, but then:

-Came back quick, readjusted that. Will STILL not idle at 15a/f like it did with the stock afm.

-Adjusted fuel pressure to 38psi no vacuum. No change, still over 18a/f off the scale.

-Adjusted the Lex afm screw all the way closed. Slight change in idle a/f.

-At cruise, it sits at 17-17.9 a/f
-At a slight incline, it sits 16.2 a/f
-I did not want to boost it but if i stepped into it a bit, it would gradually go through 15-12 a/f but i never actually got into good boost, too nervous, i feel like it's running LEAN and i'm frying things.

Or maybe that's normal and i'm just used to 550's with no lex afm? Is what i'm seeing normal? It feels good, but that's feel... AEM wideband is in the red most of the time and it just seems bad...

I'm getting super frustrated with this and I'm going to snap. What the hell am I doing wrong?

I don't have time to go over this tonight, but here's a tip. Smell the exhaust. Unburnt fuel causes a lean reading on a wideband. You are fighting with this more than someone with experience but no more than any other novice, especially when they've made too many changes at the same time. Set the fuel pressure to stock. Set the NEO to zero across the board. Look to see how far rich or low you are across the board and make a mainscale adjustment to account for that. Then trim each section as needed on an individual basis. The ECU doesn't learn how the engine is running from one single session and I believe it continually adjusts to changes as well. After the first couple drives it should be pretty well set though. Resetting the ECU when the car is cold or hot isn't going to do much it's looking at averages from multiple samples.

DON'T PANIC ;) A lean idle isn't an engine killer unless other things are wrong (no EGR to cool things down, heavily advance ignition, etc.).

Is the stock O2 sensor still installed? Or is the AEM providing the ECU with a narrowband signal? If the AEM is providing the signal make sure it's properly scaled and the wiring is rock solid... Doesn't take much to throw the signal off enough to cause the ECU to think the AFR is WAY off and perpetually over correct.

Just noticed an error I made, I said RICH when it should have said lean frying things but i think you picked up on that.

I've been driving it around, it feels awesome, and I've gotten into boost and it's actually a nice range of mostly around 11-11.5, dips to 10.5 at some points but in full boost, never hits 12. So it's actually boosting quite nicely. I think it may still be learning idle and cruise though because it has dropped from 17.9/off the chart to 17 and idle sometimes goes down to 15 but then climbs back up. Maybe it's trying. I think I'm just over thinking it and just being paranoid.

Utilizing stock o2. EGR IS removed. Is that a possible problem for EGT's? I've been meaning to get an egt gauge. Timing is stock spec for turbo engine.

Side note: Since it's running well under boost, i decided to crank the boost up to 17 and see how it goes. A/f's are still solid, pulls like a maniac. Gota be sitting up towards 400whp (basing off of my last dyno results and what i did to get there).

The question: Twice and only twice, when I hit it hard, preloading and then dropping into the boost, It puffed a decent cloud of greyish smoke. Not white, and not the black shit i used to spit out. Is this an indication of anything bad or just a hard working engine? Only a puff, didn't do it the whole pull.

I'm going to go through and make sure all my intercooler pipes are nice and tight and make sure everything else is good to go for 17psi. My only other issue is a oil burning issue from what I've narrowed down to be the valve stem seals.

Thanks!

17+ AFR is leaner than you want at idle. It may creep there on occasion on a sound setup but shouldn't spend most of its time there.

Removing EGR on vehicles made after the 70's is just ignorant or motivated by vanity. It doesn't effect performance at all while at WOT (as it's off then) and it helps cool the engine after a hard run. As for the latter... MOST people couldn't give a shit what it LOOKS like under the hood. It kills me how people try every single trick they can to increase performance and at the same time nickle and dime themselves out of power based on the opinions of some guy with a mullet, '65 Mustang and 12 pack of Budweiser in his gut. Don't worry though, it's not going to kill your engine with it removed.

Are you having any issues with AFM related error codes? Are your AFR trends significantly different after cold starts vs warm? What do you mean by "preloading"? Brake boosting? The smoke is probably either running rich or oil... hard to say without seeing it myself.

No codes or anything. This is what I mean by what the hell is my cars deal with me doing this mod. How do I go about richening up idle? it's still 17 at idle and 15-16 cruise, really light cruising 17.

Not quite brake boosting but putting a nice load on the engine then hammering on it. Just building up the boost as apposed to just waiting for the turbo, it builds more boost, quicker, so it seems that's when the most stress is on things. New note on this, I get this strange, very fast sounding, not quite a rattle, more of a grind, but not quite a grind. haha impossible to explain so I have my gopro with a remote mic and i'm going to place it in a couple spots in the engine bay and see what that noise is. It seems it happens over 17psi boost; so when i put some load then hammer on it, it spikes for a second but keeps up there and I hear it. It's only happened a couple times but if i were to take a stab at what the noise may be, I picture the compressor wheel of the turbo grinding into the housing... But the turbo is recently rebuilt and upgraded...

Cold and hot afr's actually aren't too different. Been driving it since I posted this thread, so a couple days now. Still pulls hard, feels great throughout the powerband, my turbo spools quicker a lower rpm. I just DON'T like the lean idle. I did some research, 16afr cruise isn't even bad so I'm only worried about idle at this moment.

So today randomly after pricing out some tires, it was warm, sat for about 25 mins, then i went out and shortly after, it started to have a shity idle. It has gone more lean, it's off the chart at idle now(18afr+) and it sounds like it's cammed. shaking and shit. NOW what... I didn't change anything.

Is it possible it's my fuel filter? I show pressure up to and beyond 40psi, but i'm not sure if that's a guarantee the fuel filter isn't holding it back. I'm trying to figure out why it wants to stay lean. What else could it be? I have a walbro 255 to put in but like i said, I can get probably 55psi maybe 60 and that's it. Only cranked it up to see how the 12v mod effected it.

If your AEM has a narrowband output Try disconnecting the stock sensor and run the AEM narrowband output to the ECU. Wideband AFR's aren't "off the scale" until they hit about 22... A limitation of your wideband perhaps?

No, it's not your fuel filter or pump... You'd have MUCH bigger problems under a load than when you're at idle.

Part throttle boosting often involves the throttle still being open at a low enough angle that the ECU is still in closed loop operation and adjusting the fueling trying for 14.7:1. Check that this isn't the case. If it is then yeah, the cloud is probably extra fuel from the sudden surge when you finally stomp on it and the ECU goes into open loop.

You've tuned your fuel pressure while at idle with the vacuum disconnected? What pressure are you running presently?

I'd start looking for that noise in hardcore mode... Noise isn't good. Especially if you were running lean while booting and didn't catch it (been there, done that, replaced pistons).

What are all of the settings you're running now?

Relatively new AEM wideband, sensor mounted in the correct spot/position. Just for the record.


Yes, vacuum disconnected, running 40psi. Any less and it wouldn't say below 18afr('off aem gauge scale'). BUT now it is staying above 18 at idle, no matter the fuel pressure.

As for the noise, I didn't hear it other than those first 2 times, 1 was with the boost controller setup shity, so it spiked, but did not go lean. (looked at wideband gauge when i heard the noise). Other time also not lean, but with the boost controler setup properly, at 17psi, but with a preload on the turbo then stomped on it, it may have boost spiked but it didn't go lean so i'm not worried about the pistons at this point, although i do want to do a compression test just to rule any of that out.


Settings as in for what?
-Greddy profec b 2 is setup to boost to and hold 17psi (no spiking or creeping or dropoff after an hour or so of tuning it)
-NEO is setup for 0+/- across the board but also turned compensation off, so no fuel compensation but naturally it's still rich in boost with the 550's + lex afm.
-Fuel pressure 40psi (no vacuum, at idle)(also has 12v direct relay mod)
-ECU was reset when i initially installed the lex afm(about 6days ago, i haven't driven it the past 3 days)

Oh, I assumed you'd started working with the NEO now. Increase the fuel of the low load map from the first set point up to the 800RPM cells in 5% increments. See where that takes things and then worry about the fine adjustment after you get close to the desired results.

I didn't realize you also had an EBC in there. Personally, I'd disconnect it and tune the system for stock boost first.... but that's not a significant concern if you've already got it set up and running properly.

Well I intend to run 17psi so I want to tune for 17psi.

And i've been told by many not to touch the low throttle input for the neo, letting the ecu handle that, instead of having the ecu fight my adjustments, and just tune hi throttle.

Either way, that's not my issue, my issue is ONLY my lean idle, and lean cruise.

Compression test = Check.
Boost leak test, 25psi = Check.
Different afm test = check(no difference)
AFM cleaned = Check(no change)

Found a small vacuum line that feeds the boost control had blown off the manifold, that's why the idle was shit after I left the mechanic and did a pull, blew it right off. Car is new to 17psi so there's one thing checked off. Ruffed up the fitting and zipped tied, Check.

I notice randomly it sometimes has a good idle, 15ish, max 16. Then other times it sits 16.9-17.9.

Also I have not heard that noise more than those first 2 times.

Tune the low maps so the ECU isn't working too hard to get the proper AFR. Also, you need to tune the low and mid maps to get somewhere close to 14.7:1 as the ECU isn't always in closed loop in those ranges. You can't stray much from what the ECU wants the AFR to be at in the low and mid maps but yes, you need to tune them all. For the high loads (about 70% throttle or more) you can tune for whatever AFR you like. My preference is to tune the mechanical hardware to get as close as possible across the whole spectrum and then us the fuel controller to fine tune everything. Try unplugging the stock O2 sensor feed to the ECU (forcing the ECU into full time open loop mode), tune after a cold start, aim for 13.5ish for the low map and 14.5ish for the mids, reconnect the O2 sensor.

Do NOT try to clean the AFM. You can blow the honeycomb out with some compressed air but NO cleaning solutions or solvents. The sensor is optical and if the cleaner enters the sensor or fogs the lens the entire thing may be ruined or way out of whack.