ECMlink Running lean at idle

[TalonEsi_96]

I have been trying to figure out why my car is running so lean. It was recently running about 14.9:1 - 15.4:1 at idle which was lean but not horrible. I figured it was because a leak I had in the throttle body so this weekend I swapped it out and also replaced my diaphragm on my Greddy Type S with an NGR. Now I can't get my wideband off 18.3:1 and did a BTL but couldn't find any major leaks. My car is a 2.3 stroker so would I have to adjust anything on link? I am getting my 1200cc injectors back this week from FIC and am going to try to put those on incase my stock injectors are clogged but it was fairly fine before so not sure why its so off now. I have a 5 hr drive tomorrow and want to try to figure this out because I don't want to drive it like it is. Also I have an AEM Wideband so maybe thats going bad? Looked at my plugs and they looked a bit lean but not major. Thanks for any help guys!

 

[miliman13]

Are those fender flares ? if so show them of.
But on your link log, you AFR @ idle looks ok, so it may be your wide-band.
On cruise, i did notice you go super lean at certain points, but perhaps that is do to shift points ? any one else, want to help interpret.

Stock cams?

 

[TalonEsi_96]

No fender flares and yes stock cams. I am really hoping its just the gauge so I don't have to worry too much. My compression is bumped up a bit 8.7:1 I believe not sure if that changes much. I just want to make sure its fine to drive 5 hrs to college because i'm going to try to take it to MAP to get tuned in a few weeks.

 

[miliman13]

cool i guessed right on the cams, based on the log.
Well nothing really stands out as DANGER except for those AFR spikes but it looks like your shifting there. Ultimately it's up to you if you want to make the drive, i just picked up a 2nd car in the meantime so i don't run any risk with mine until i'm content with it.

 

[TalonEsi_96]

Everything look good in link then? Or should I take it for a spin and maybe do some different driving? Like I said it seems to be driving better than it was but I didn't drive too long because of that A/F ratio.

 

[c2ypt1c]

From what I can see, the things that jump out are your wideband and ISCPosition. I'm not sure if your linear wideband settings are correctly defined, so I'll ask...does the logged AFR match the gauge? If so, try checking for a pre-sensor exhaust leak. It looks like the frontO2 is cycling properly and therefore maintaining a 14.7afr, so I would think it's an issue with the wideband.

Secondly, your ISCPosition is at 0. You should adjust the BISS at the throttle body and get it up to around 30 at fully warm idle. Do it slowly and in small increments.

In regard to tuning, it looks like you need to raise your mafcomp sliders at idle (0-50hz). CombinedFuelTrims are a little high/airflowperrev is a little low for a 2.3L. Shoot for 0% fueltrims and 0.28-0.29 airflowperrev.

 

[TalonEsi_96]

The gauge and what it reads on link is fairly close maybe .1 or .2 difference and regarding the ISCPosition I had it right at 30 before and it seems to change on me, maybe a faulty IAC? I'll try readjusting it tomorrow and see if it will stay. I just had my exhaust done so there shouldn't be any leaks but that's what I originally thought was causing a lean reading but apparently not. Thanks for the help guys I really appreciate it!

 

[c2ypt1c]

The gauge and what it reads on link is fairly close maybe .1 or .2 difference...I just had my exhaust done so there shouldn't be any leaks but that's what I originally thought was causing a lean reading but apparently not.

Yeah, in that case I'm thinking the sensor might be taking a dump, if your AFR were really 18 or higher, there's no way the frontO2 would cycle normally, not to mention you have a solid idle rpm...time to go with an innovate or replacement sensor (sorry, I'm biased toward innovate, I've had nothing but good experiences with them)

Oh the other thing I forgot to mention was you might want to do a TPSadjust

 

[TalonEsi_96]

Just ordered the Innovate LC-2 so hopefully this week I can install it and get this figured out. I'm also going to order a new IAC if I can't get it to stay where it should. Thanks for the help big time!! Also my TPS volts will be at .63 then after driving it will change a bit higher or lower when coming to a stop is this normal? Or are these symptoms of a TPS sensor going bad?

 

[c2ypt1c]

Also my TPS volts will be at .63 then after driving it will change a bit higher or lower when coming to a stop is this normal? Or are these symptoms of a TPS sensor going bad?

Heh, I had the same exact problem before my timing belt snapped, don't worry it's completely unrelated (obviously right?). All I can say is the problem wasn't there after I reinstalled the head and got it back up and running.

Here's what I did, that could have contributed to the solution:

Completely removed the tps and readjusted it during install.
Reattached and adjusted the thottle cable.
Removed the useless cruise control solenoid/cables.

Wish I could give you a definite answer but hopefully this can help you track it down.

 

[TalonEsi_96]

Thanks man I'll keep those in mind as I hunt down the solution.

 

[TalonEsi_96]

Figured instead of starting a new thread i'll add to this one. I just recently installed my Lucas 1200cc injectors and can't for the life of me get the deadtime right. I had them flow tested and they flowed at 1160cc so i used that for my global but to even get the car to idle i'm at 700+ deadtime which I'm thinking is way too rich because now my AirFlowPerRev is very low so my o2 sensor won't cycle. If someone could give me some pointers that would be great also the car is surging a bit now which I am assuming is because the deadtime and maf comp are all messed up. I also have no boost leaks and installed a new IAC even though that count flucuates on link will try to adjust that more once I can get these injectors to idle. Also i'm on 91 pump gas as thats all that is available at the moment.

 

[Archer Fabrications]

If your needing 700 dead time to make the car just run your global is seriously out of wack

 

[TalonEsi_96]

So even if my injectors were flow tested to 1160cc I should still mess with my global settings? I just used the calculator on ecmlink to come up with my global settings and used 1160cc and 43.5 psi of pressure which is what my AFPR is at. I know I shouldn't have deadtimes that high which is why I would like to know whats going on.

 

[Phantom DSM]

So even if my injectors were flow tested to 1160cc I should still mess with my global settings? I just used the calculator on ecmlink to come up with my global settings and used 1160cc and 43.5 psi of pressure which is what my AFPR is at. I know I shouldn't have deadtimes that high which is why I would like to know whats going on.

What is your global set at ? Im suing this formula right now :
Global = (100 * ( 450 / NewInjFlow ) ) - 100
= (100 * (450 / 1160) ) -100
= -61
Start with -61 global and 330 deadtime then adjust from there for low combined ft...27-.28 airflow per rev is to be expected from a stroker motor

 

[TalonEsi_96]

I have it at -62.5 and if I set my deadtime to 300-400 it won't start/idle very well but I will try your formula in the morning and see if I can get it to run properly. If it doesn't start or stay idling does that mean I need to increase deadtiming? Thanks for the help btw!

 

[c2ypt1c]

So did you get the new wideband installed?

From my experience, the global fuel that link suggests is not always correct. There are too many variables between different setups to define a static number.

What I'm about to tell you is my own personal method that I use to achieve a reasonable global fuel setting. In order for it to be accurate, several conditions must be met:
1. An accurate wideband sensor being logged.
2. At idle, mafcomp (or vetable for sd) should be set so that airflowperrev is at an appropriate level (usually 0.25 gm/rev).
3. Voltage offset data (provided by manufacture) OR a good estimation of deadtime.
4. A steady fuel pressure that increases linearly with boost - meaning a good afpr and no injector overrun at idle.

Provided you meet the above conditions, you can lock the ECU in open loop at idle, then adjust global fuel until wbfactor is around zero.
This will provide a very good starting point to get closed loop (idle/cruise) dialed in. You can then verify global fuel by ensuring mafcomp or vetable values are within a reasonable range during open loop (wot).

An alternative method that can be used without locking the ECU in open loop is to adjust global fuel until short-term fuel trim (STFT) hovers around zero. This can be useful if you don't have a wideband or if it's inaccurate (AEM )

 

[Phantom DSM]

Global is actually affected by LTFT...if your ltft is in the +10% for example you want to take global closer to zero. The global might end up in the - 50s by the time your settled.
Deadtime will be affected by STFT, adjust deadtime up or down until stft is close to zero.
Watch LTFt at the same time as well and make a balance . You should see Combined ft get close to zero as well.
Make sure the motor is past 183 degres so fuel trims can adjust properly and airflow per rev to .27-28 for the 2.3 stroker you got.

 

[TalonEsi_96]

Figure I'd update this a bit. Found that one of my injectors wasn't seating properly causing my erratic idle/deadtime. So I got that fixed but am still hearing a hissing noise from one of them so i'm going to boost leak test tomorrow and see if its not sealing right. Also I did get a new LC2 wideband and it should be logging properly. Also i'm thinking my AirFlowPerRev is low because of a boost leak so i'll verify that tomorrow. Here's a current log and i'll update it tomorrow after my BLT findings. Thanks for the help guys.

 

[c2ypt1c]

Global is actually affected by LTFT...

Not sure what you're trying to say here but global fuel is not affected by fuel trims...it's the other way around.

Are you saying that global fuel adjustments have no impact on STFT? If so, you're wrong.

LTFT is essentially the weighted average of STFT, so any changes to fuel adjustments are first going to affect STFT and then will be applied to LTFT. So the statement "LTFT is for global, STFT is for deadtime" is technically wrong. I can see why people would think this though because global is usually set first and then deadtime is adjusted dynamically. With my method however, we're doing the opposite.

 

[miliman13]

Hey, when i was trying to dial in my idle and meet the basic core requirements for certain ratios and percentages, i did not use the recommended guide from ECM Wiki.

here is what they recommend.

Fuel Injector Clinic (FIC) SIZE: [750]
Global:[ -40] Dead-time: [330]

I found a better mix around 315 Dead-time and -32 Global But with crazy low Hertz on my MAF sliders, around -45 on the 1-3 sliders.

this is how i got to .30 load .28 Airperrev and +/- 1 on combined F/T

just as i refference i bring this up, to give you an idea.
if you want to adjust your fuel do it slowly, and adjust Maf sliders simultaneously....

 

[Phantom DSM]

Not sure what you're trying to say here but global fuel is not affected by fuel trims...it's the other way around.

Are you saying that global fuel adjustments have no impact on STFT? If so, you're wrong.

LTFT is essentially the weighted average of STFT, so any changes to fuel adjustments are first going to affect STFT and then will be applied to LTFT. So the statement "LTFT is for global, STFT is for deadtime" is technically wrong. I can see why people would think this though because global is usually set first and then deadtime is adjusted dynamically. With my method however, we're doing the opposite.

Relax, im only wording it this way as he is tuning live while idling to get ltft and stft close to zero as possible. Adding in and subtracting in increments usually narrows it down...regardless just shooting for Combined ft close to zero. Just to clarify my bad though, on the 1g i usually use LTFT Lo actually just for sanity check.

 

[c2ypt1c]

Relax, im only wording it this way as he is tuning live while idling to get ltft and stft close to zero as possible. Adding in and subtracting in increments usually narrows it down...regardless just shooting for Combined ft close to zero. Just to clarify my bad though, on the 1g i usually use LTFT Lo actually just for sanity check.

The point that I'm trying to get across is that fuel trims are irrelevent. All fuel trims do is tell you how much the ecu is compensating to maintain 14.7afr, based off of o2 feedback in closed loop. WBFactor at open loop idle does the same exact thing...

 

[TalonEsi_96]

So I found that one of my injector seals tore during installation so I got that fixed today along with a boost leak at my throttle body. Car runs and idles better now but still has a hesitation at partial throttle? Also found a slight exhaust leak between the o2 housing and downpipe so hopefully this week I can get that fixed. Log looks a lot better now and once I get cleaned up from work i'm going to take it for a cruise and do the maf comp adjust and see how it runs then. Any suggestions welcome and again thanks for all the help.