Very Rich AFR's at Idle and Low Load

[HolyCrapItsFast]

Soapy water always dries up or spatters when I spray it on a hot exhaust. I can never tell if it is a leak or the water is boiling. The smoke works well for me. :tup:

A leak before the O2 makes a lot of sense.

If there is allot of valve overlap you will get a brief moment of negative pressure. I'm not familiar well with the overlap of the 08+ with the addition of the exhaust AVCS but on the earlier models there is not much. I think the engine configuration and the firing order have more to do with why it pulses at idle but i'm just speculating now.

 

[Vermont]

I will be taking to the on post work shop again and testing my theory of an exhaust leak as well. only thing that sucks is, I will not be able to put a new exhaust gasket in until Wednesday. If it is not a leak..... Well thats why I am going to get a log. I am thinking I might just turn off CL learning if that turns out to be the case. An idea what type of harm this might cause?

I really did think you were fucking with me about the incense smoke.... Makes sense now that I think about it more though, as the smoke would drift up and into the leak.

 

[HolyCrapItsFast]

Well we are here to help so please let me know how it works out.

What type of harm running rich would cause or zeroing CL?

 

[Vermont]

Well I was thinking that if I just zero out the "A/F Learning #1 Limits" table. That way even though the ecu might think that I am running lean. It will be unable to to anything about it since the A/F Learning limits will be zero.... Only problem I see with that is atmospheric changes could cause lean situations. At least though I would be able to get on with the task of tunning the EWG until the exhaust leak is fixed. If that is what it turns out be be. What do you think?

 

[Vermont]

https://docs.google.com/leaf?id=0B1sR5qgX5JgYZGQyMWExYmMtNDgxZi00ZTkzLTg1NWYtNWNmMWFkMDU0ZTZm&hl=en_US

https://docs.google.com/leaf?id=0B1sR5qgX5JgYODVhNzAzMDItYzU0Yi00NGMxLWFkMzAtNmJhNDRjMWQ1NDRj&hl=en_US

Here is my log I took. Only last about 6-8min Was just driving around post. Never went into OL during log. Let me know what you think from this man. Ima be finding out if the subaru dealership has any exhaust gaskets in stock. If so ima pick them up and replace the 2 that are before the O2 sensor.

 

[HolyCrapItsFast]

During this log did the wide band read very lean at any point or was it rich the whole time.

There is a long stream of data that is very lean and the ECU is over compensating. As you suggest, if the wide band is reading rich, this would be a leak pior to the O2 sensor or a bad sensor itself.

 

[Vermont]

Very very rich. To the point where, in that short time I was logging there was a noticeable drop on the fuel gauge. The wide band was reading 10.0 the whole time, which is as low as the gauge will read. I am trying to get a hold of Jordan at Defined and see how soon he can get me those new gaskets. Gonna replace all of the ones on the passenger header. If that does not fix it then I will also pull the O2 and replace it as well. O well lets see what happens.

 

[HolyCrapItsFast]

Yes I would be very interested in the outcome!

 

[Vermont]

No matter what the out come is man. I have to say thank you for all the help man. You have been a huge help. Also I think I got the boost all sorted out. I was testing it out on the way back from that log. Re-flashed with that rom I linked on, dropped WGDC 30% across the board. Then lowered max boost down to 20.5 psi and raised some of the lower load boost values a little. I am not sure if you can read that .Hex though since it is based off a XPT tune.

 

[HolyCrapItsFast]

My pleasure! you did all the diagnosis and figured it for the most part... I just helped confirm. :tup: I hope this does it for you. I can't imagine it being anything else.

I couldn't read the ROM. Says I don't have the right definition file.

 

[Vermont]

If you get a chance to look at my rom that would be awesome man. Any things you think might be good to change let me know. here is the def file for romraider.
https://docs.google.com/leaf?id=0B1sR5qgX5JgYYjA5MGMxZTctYzM4OS00NWVkLWEwMzgtZGQwNGY0NGRkY2Jh&hl=en_US
I have a lot more logging I will be doing before I call it good with this tune.
Mods are as listed:
09 STI
AEM CAI
Megan Racing Catless DP
Borla Cat-back
Grimmspeed Up-pipe
Tial 38mm EWG /w Dump pipe

 

[HolyCrapItsFast]

Okay that worked...

I don't see anything that jumps out at me that would make me think it is not safe. I would have made things a little leaner in the fuel table but that is just my preference. Can't speak much on AVCS. It seems to be different for just about every ROM I lay eyes on. The settings I've used in the past look very different. AVCS is such a completely custom thing and what works for me will not work for you. This is an area of the tune that I need work on. Finding the right information is challenging at times.

If it is working for you and AFR's are close to target and there is no knock, it is good.

 

[Vermont]

I am keeping the AFR's a little rich for now due to the fact that I am still messing with the boost and WGDC. I would rather not start knocking my engine off becasue I tryted for more power right now. What I was thinking is to lean out the AFR's a little (E.I. closer to 10.8/11.0). But I want to get the timing on dead first. Even the Suby tuner guide I have been using does not have very much info on AVCS.

 

[HolyCrapItsFast]

Well the thing with adjusting timing is you should do it with the fuel stettings you expect to eventually use. So you would adjust all your fuel parameters first and then visit timing.

The thing with adjusting timing on a richer map is that when you do readjust your fuel to be leaner you could wind up knocking at that point. Also if you readjust your fuel targets you will need to go back to MAF scaling to calibrate your MAF curve to the new targets.

 

[Vermont]

Arg never thought of it like that. So when I tune my fuel I set it to the place I am going to want it in the end. Then I do the timing last so I wont knock. Unless my fuel targets were too lean in the first place.

 

[HolyCrapItsFast]

Pretty much... Yes. The most important thing is the air and fuel. If that isn't right from the beginning, nothing else is. Everything else is dependent on and adjusted off that. Pretty much the only thing that really impacts fuel after the fact is AVCS. When you make adjustments to that you always have to go back and confirm and/or readjust your air/fuel because your effectively changing VE.

Boost also has some effect on air/fuel after the fact so it would be a good idea to just go back and confirm your air/fuel under a boost condition once you have made final adjustments to boost.