houstonrx8er

iTrader: (8)

Situation-

For a while now I have had an issue when cruising my AFR's will drop to the 11-12 range randomly.... on flat roads.... with no variance in throttle input (happens with or without CC). It is more frequent after everything gets warmed up (+20min drive). When it goes rich all I have to do is let off the throttle for a sec and everything goes right back to target AFR then returns back to rich in the next min or so. Also if I thrash on it starting from 1st gear the AFR's are spot on...its only when cruising, in just about every gear and just about any RPM (within reason)

I have replaced all the injectors, the entire fuel pump assembly, plugs, MAF, front O2, tried reverting to different tunes (stock-COBB-custom), checked for vacuum leaks, checked for loose grounds...etc

History-
N/A, ported, 10k miles, battery relocation, BHR Ignition, periodic premix, sohn,

My steering does have random issues that I have been unable to permanently resolve (mind of its own)

Only guess I have left-
My steering is creating an electrical interruption
some sort of Grounding issue I haven't been able to locate
bad BHR
there was a thread that mentioned water in fuel (which I highly doubt)

I plan to drive around with the steering disconnected and also take some datalogs while it happens, I will post them up shortly.

Can anyone offer any advice

roflcopter

iTrader: (2)

I know this doesn't help you at all, but my car does the same thing.

I have another issue that I thought was causing this as well, but I guess since you aren't having that along with it makes me think they are unrelated issues.

Let me know if you end up figuring anything out with this.

EDIT: From my data logging the rich condition is caused by the car deciding to switch to open loop, it also only occurs at rpms over 3k or so from my experience, it takes longer to happen at 3000 than 3500 or 4000 as well.

Brettus

iTrader: (2)

normal

houstonrx8er

iTrader: (8)

really..lol

I love normal...make me love my car even more :D

Brettus

iTrader: (2)

if you log stft i think you will see it go to zero at that point which indicates open loop.

houstonrx8er

iTrader: (8)

You are correct...I can watch that on my goodbox. Does that represent an ecu issue possibly?

Kane

iTrader: (1)

High load, low RPM? That is pretty common and hard to undo, because only the Fuel VE% map can pull that fuel, which is bad when you are actually getting on it.

Does it misfire or feel sluggish?

houstonrx8er

iTrader: (8)

It doesn't misfire but it is sluggish when I get on it and the afr's are 11.2....lol

was able to reproduce it in rpm from about 3-6.5ish ....it did do it a few times in the 7k range but not near as consistently.

It just doesn't seem right that I can't make a road trip at 77 without running in the 12's....horrible gas mileage

Kane

iTrader: (1)

What throttle position?

Also, check the Injector DC, before and after the bog, if it is lower AFTER, that is an indication that the secondary injectors are dumping too much fuel.

HiFlite999

iTrader: (2)

I had a similar AFR problem with ~70 mph cruise. It went away when I removed the vented-to-air oil catch can that I'd installed.

Brettus

iTrader: (2)

If you have a positive LTFT this is contributing to it . So you can lean it up by rescaling the maf to eliminate the trim .Then again you may have something causing that trim which should be fixed .Not to mention that the rest of the tune will get offset by the same factor if you change anything. It's called ............ tuning

Also - you can adjust the fuel map in that range to 14.7 if it isn't already.

Assuming you have your injectors scaled correctly ?

houstonrx8er

iTrader: (8)

of course I couldn't get it to do it when I am ready to log...going on a long drive later today, we shall see what happens

I dont have one but excellent info man thanks! :D

I loves me some tuning and yes its currently set to 14.7 in that range. I did go back and re-scale my MAF (turns out I didn't re-scale it all the way when I replaced it...dumbass). My Bank 1 was less than 1% off and I will check the other banks in just a few (its starting to rain)

Just had a thought talking with 9k...I have the APV stuck open code P2004, despite following the TSB the code will not go away (APV are ported and I always assumed this was the driver)....is it possible my APV closes randomly creating the issue rich issue?

I am going to swap it out with a spare I have handy just for ***** and giggles...keep you posed

houstonrx8er

iTrader: (8)

well I am not sure if this log is going to help. I tried to get the log started before the "event" happened but I couldn't do it...then I ran out of road getting my daughter.

I will try again when its not raining but in the meantime let me know your thoughts

9krpmrx8

iTrader: (46)

It's kind of hard to read but your injector DC looks to go a bit whacky in those rich spots.

Brettus

iTrader: (2)

The AFR column numbers make no sense to me ?

9krpmrx8

iTrader: (46)

AFR's are 5th column over, the formatting of the column headers is jacked up.

houstonrx8er

iTrader: (8)

sorry I suck

houstonrx8er

iTrader: (8)

the wackiest spot

9krpmrx8

iTrader: (46)

And if you look at the data before and after there doe snot appear to be anything strange like a drastic reduction in data because he took his foot off the gas, came up on a huge hill, etc.

9krpmrx8

iTrader: (46)

http://www.flickr.com/photos/9krpmrx8/8638867974/

houstonrx8er

iTrader: (8)

and next time I will use paint ...sorry for being a log posting noob....lol

houstonrx8er

iTrader: (8)

even the SARX logo...killing me 9k...lmao

9krpmrx8

iTrader: (46)

Brettus

iTrader: (2)

I still say that is reasonably normal behavior as it goes into open loop . Although it is richer than optimal which could be any one of a combination of things

injector scaling or latency
Maf calibration
VE
OL fuel table
Some gremlin in your setup EG a leak.

Thing is to rule out each possibility using a combination of trial and error and logic .

houstonrx8er

iTrader: (8)

this logs really isnt the best representation of what I am experiencing but it was the only log I could get thus far.

my Maf is calibrated to 1% based on FT and the bank1 and bank2 are within 2% target AFR's when I do my logs.

being that it does this on the stock map I assume the VE table is ok (is that a fair assumption)?

I guess I will go on a leak hunt...again. I really appreciate your assistance