Troubleshooting lean condition on turbo H22

[Raf99]

Agreed.

So it's a simply question. What usually stops the A/F from going too lean after returning to idle. From what I read it's a combination of sensors. And i've been reading for days.... weeks. And simply put this is why ya pay the professionals the big bucks. It's called experience. But we are just having fun here. I asked the tuner if he had an old datalog but he did not. What i need to figure out now is if it will display the same symptoms as last year, which was the hotter it got the more lean. I've read many pages where someone had almost the same symptoms.

Does anyone know of a program i can use to record my active window on my laptop?

Edit: Boost gauge is normal setup.

[Rilas]

This would probably be your best bet.

Free, no water marks, limit of 10 mins on videos. All of which should work fine for recording the tuning software.

http://icecreamapps.com/Screen-Recorder/

If you need longer videos you can always just save 2 and merge them together with other software.

[toycar]

S.trim = short term fuel trim = only used in closed loop to achieve stoich

Progressive rising, in my opinion, is indicative of bad O2 sensor. Why? You aren't doing anything else continuously. Blip throttle, splash of gas hits the cylinder and car is trying to transition to closed loop, which is what you are seeing in the tune when S trim rises and drops. Nothing else is happening at that point though, and your map is reading fine. So, what else could tell the ECU to keep chasing the problem? The last thing to measure anything, the o2 sensor. It is something in your closed loop for sure, and the o2 sensor is the only thing that could continuously contribute to the S.trim varying without other stuff happening. If the crank or cam position was reading incorrectly, the ecu wouldn't slip into closed loop and most likely it wouldn't run at all.

TPS isn't showing an issue after blip and is accurately logging. MAP sensor shows appropriate logging as well.

What else is there to consider in a closed loop tune? Intake air temps, H20 temps and A/F mix. If it was reading cold, you would have other indications and again, you wouldn't be able to sneak off into closed loop(Most likely).


So, engine position is being managed by crank and cam position through dizzy. Airflow is being measured using MAP sensor that both ohms out and is logging correct trends in correspondence with your TPS.

Engine temps and IAT temps are acceptable on the log, so even If there was an issue with either of those readouts, they wouldn't be acting up right now. Temps are good as far as ECu is concerned.



The s.trim is rising and then falling, chasing a problem it is trying to auto correct. Why is it auto correcting?

What readout from what sensor tells the ecu to add or reduce fuel?


O2 sensor.


This is only happening in Closed loop.


O2 sensor is giving feedback on closed loop.


All signs point to O2 sensor. Do you have a buddy you could swap with to see if I am right?


New o2 sensor is less than a hundo, a battery or an alternator. I would replace the o2 sensor if it was me.

[93redcb7]

yea just replace your wideband o2, its not to crazy expensive, as we have already discussed is likely the cause

[Raf99]

This would probably be your best bet.

Free, no water marks, limit of 10 mins on videos. All of which should work fine for recording the tuning software.

http://icecreamapps.com/Screen-Recorder/

If you need longer videos you can always just save 2 and merge them together with other software.

Thanks!

S.trim = short term fuel trim = only used in closed loop to achieve stoich...............
.....
........ bad O2 sensor. .....O2 sensor............
O2 sensor.

This is only happening in Closed loop.
O2 sensor is giving feedback on closed loop.
All signs point to O2 sensor.

Do you have a buddy you could swap with to see if I am right?

New o2 sensor .....replace the o2 sensor if it was me.

yea just replace your wideband o2, its not to crazy expensive, as we have already discussed is likely the cause

Ok, I hear ya. And thank you. But I did bench test the O2. It did pass.
I do not have a bud to trade with. But I certainly don't mind ordering one. I just need to figure out ... which specific model I have.

[Raf99]

with all this O2 talk, found this on my searching tonight.. identical symptoms. The O2 ghost...

http://www.evolutionm.net/forums/aem...02-sensor.html

[93redcb7]

sometimes o2's get "lazy"
had it happen on me once, it would read fine and everything.. replaced it and everything went back to normal

[Raf99]

So as we say up north, Bob's your uncle. New O2. But talking to the tuner today and he had some ideas. 1. Just turn off the O2 while in closed loop. (O2 correction). That will tell you if it's the O2. And... he thinks it's fuel but also has had this same slow O2 issue
Anyways, he was helpful as usual. I didn't want to bother him as he was trying to tune another car at 5:30pm on a friday. So I'll wait for a nice day and let it warm up again. Prob this Sunday.

[Raf99]

As per tuners request, vids of the O2 disabled in closed loop vs. enabled. I won't say anything and see what you guys think

Car is warmed up. O2 on in closed loop.


O2 off in closed loop

[GTRON]

As per tuners request, vids of the O2 disabled in closed loop vs. enabled. I won't say anything and see what you guys think

Car is warmed up. O2 on in closed loop.


O2 off in closed loop

I don't even know what this thread is about, but that exhaust sounds great.

[Raf99]

I don't even know what this thread is about, but that exhaust sounds great.

lol... thanks man. I've heard mixed reviews. Some say it doesn't sound like a 4-cylinder and others say it does. It's the 3" exhaust that makes it sound unique. But this summer we will be adding a resonator to the mix, to quiet things down.

[toycar]

yay, so it seems like the o2 has been confirmed the culprit? car seems to be fixing the lean/idle issue with o2 disabled.

Woot, hope this is it!

[Raf99]

yay, so it seems like the o2 has been confirmed the culprit? car seems to be fixing the lean/idle issue with o2 disabled.

Woot, hope this is it!

Hear that! Night and day difference! So this week I'll put the new one in and see how it reacts. There's still a chance that there could be issues even with the new O2. But having a "lazy O2" sucks ass. Seems to have a mind of it's own.

[93redcb7]

yea its coming right back to normal with it disabled, though it is on the lean side when your just barely on the throttle, though that could just be the fuel mapping not compensating for a addon part after you had it tuned or something.
but with the o2 enabled it will be fine since its search for a lambda signal. to adjust fuel

[Raf99]

yea its coming right back to normal with it disabled, though it is on the lean side when your just barely on the throttle, though that could just be the fuel mapping not compensating for a addon part after you had it tuned or something.
but with the o2 enabled it will be fine since its search for a lambda signal. to adjust fuel

Ya, i seen the lean too. Not sure what's up with that, the car was sitting all winter. I did add a new ECT sensor. I'm not worried about it at this point.