Help with Log/DAM

[Zwagoner3]

I just posted this over on NASIOC as well. I have a 05 LGT 5speed that I have owned for about 2 months now after the tune. Tune was done by Dom at Maxwell Power Services in Marysville, WA(before he moved) I have been experiencing some knock and my DAM value has dropped. The worst I saw was .500, it is now at .875. I didn't see much knock on my log, I have seen it go to -12.00 at times. The car also idles rough when warming up and smells rich. Surges a little around 2,000-2,700rpms. Last week I had a misfire in cylinder 4. I reset the code and it has not been back since.

Mods:

VF52

Walbro 255LPH

Deatschwerks 740cc injectors

Perrin top mount

Cobb SF intake

ERZ downpipe

AEM EBCS

Grimmspeed TGV delete

Stock catback

Uppipe(don't remember brand)

Made 327whp at 18PSI at 36 degrees around sea level

Here are two logs I just did in 3rd WOT, hopefully someone can help, thanks in advanced.

https://docs.google.com/spreadsheet/ccc?key=0An_AmTgEjJdWdEo5X2tySmhDU0JDVDFHV0pLeW11MGc&usp=drive_web#gid=0

https://docs.google.com/spreadsheet/ccc?key=0An_AmTgEjJdWdFBOQ1lEUTFvYTZhc0F4ZERfeVhrcFE&usp=drive_web#gid=0

Thanks,

Zach

[serx7]

Your mods are very similar to mine. iNVAR will probably see this thread and provide some input w/ the logging , but you should probably post a Live View screen shot so we can see your fuel trims for starters. -12.00 deg pulled timing is significant (possibly false) knock. Do you have that in a log?

 

When I bought my 05 OBXT last summer, it too idled poorly during warmup (and kept stalling upon disengaging the clutch coming to a stop afterward) and it reeked of fuel always. The boost hose under the intake manifold (where the infamous blue T fitting is) had popped off, and the PCV was completely disconnected from the crankcase.

 

Reinstalling the boost hose fixed the poor idle (more or less, but a subsequent protune revealed incorrectly scaled MAF/injectors) and reattaching the disconnected PCV completely fixed the fuel smell.

[Zwagoner3]

Your mods are very similar to mine. iNVAR will probably see this thread and provide some input w/ the logging , but you should probably post a Live View screen shot so we can see your fuel trims for starters. -12.00 deg pulled timing is significant (possibly false) knock. Do you have that in a log?

 

When I bought my 05 OBXT last summer, it too idled poorly during warmup (and kept stalling upon disengaging the clutch coming to a stop afterward) and it reeked of fuel always. The boost hose under the intake manifold (where the infamous blue T fitting is) had popped off, and the PCV was completely disconnected from the crankcase.

 

Reinstalling the boost hose fixed the poor idle (more or less, but a subsequent protune revealed incorrectly scaled MAF/injectors) and reattaching the disconnected PCV completely fixed the fuel smell.

 

I have not caught it in the act yet, it seems very random when it decides it wants to have issues, I will check the PCV tomorrow though, how are you doing for MPG? I'm only avg 16mpg and thats mainly highway. Not sure if the mods and this car are that bad in mpg or I have a leak somewhere?

[serx7]

for stuff like that you'll probably just want to start the log and let it run the whole time you're driving. afterwards, review and paste excerpts that contain any interesting/concerning parts.

 

I avg 24-26 mpg, depending on how much I tach it b/n fill ups. Most of my commute is highway, avg speed is usually 75-78. I usually tach it through 2 or 3 gears to 4500-5000 a couple times daily, moreso & w/ higher rpm if I'm data logging for something in particular.

 

See if you can get a LV, or just do a short log while idling, logging AF Learning 1 A, B, C, D.

[Zwagoner3]

When at an idle this is all the numbers.

 

A/F Learning 1 is -5.47

A/F Learning A is -5.30

A/F Learning B is -2.10

A/F Learning C is -6.90

A/F Learning D is 0.00

[Zwagoner3]

Could the PCV be a problem? Or maybe an O2 sensor? It pulls nice and hard with no hesitations. But cruising it's not as smooth. My A/F is in the 14s cruising.

[serx7]

Those #'s don't seem that that bad, generally ppl say +/-10% is sort of decent with +/-5% being pretty good. I think usually if there's a post-MAF leak you'd see positive A (engine sucking in more air under vacuum than what was metered by the MAF), with negative B/C (engine leaking air under slight positive pressure than what was metered by the MAF). This was my situation until I noticed one of the o-ring gaskets on my Perrin IC spacer had partially disintegrated (part of it was actually sticking out from the IC inlet flange). My A trim still hovers in the +5 to 6% range but the B and C trims have come back in line after several days of driving. Before they settled out to -4.x% and -8.x%, now that I replaced the marginal o-ring, they've settled out to around -2.1% and -2.6%.

 

When I first smelled the gas, I thought it was b/c the only cat I have on the car is the one in the catted Cobb DP (UP is catless, and I have a Nameless resonated midpipe/Y in place of the stock catback). After a day or so, I realized the gas smell was emanating from under the hood (it was coming in through the vents), and I was able to quickly localize the source to the PCV that wasn't attached properly.

[Zwagoner3]

My logs don't look bad, my DAM is down, but I don't get any knock WOT. It almost acts like it's getting too much fuel lower Rpms without much throttle then when I give it full throttle it had no problem eating the extra fuel. 16mpg seems low but that's just a guess. But my A/F ratio seems good. Any chance a loose pcv would cause all this? I will try and check it today after work. I hate taking my perrin TMIC off. It's a PITA to fit it.

[serx7]

DAM/IAM being less than max means at some point there was enough knock for the ECU to pull timing back across the board. Unless it was just a bad tank of gas, something is wrong & needs to be diagnosed & fixed. I don't think a loose PCV would cause the DAM drop, but I'm really not sure. My PCV was disconnected where it attaches pointing straight down on the motor, I could see where it was disconnected by looking down into the space bn the intake manifold & the TMIC. Fortunately I just had to loosen the TMIC and I could squeeze my fingers into the space enough to push the PCV back on.

[Zwagoner3]

I'll reset my ECU and log all the way to work tomorrow and see if it comes back. I've reset it once before from .625 and it went back to .875.

[serx7]

I've been around tunes that set the initial DAM/IAM to 1 for so long, I neglected to consider that your tune might actually have the initial DAM value set to something lower than 1 to start things conservatively after an ECU reset. If that's the case, probably no need to do the ECU reset, and I apologize for being alarmist regarding your IAM being < 1.

 

If you do perform the reset and the initial DAM is 0.625 as you mentioned, it should climb to 1 eventually if the the car is running OK. Back when I was troubleshooting suspected false knock at low loads and low rpm, I noticed my DAM had dropped to something like 0.5. A short time later I started the car up, accelerated moderately for several seconds and saw DAM quickly climb back up to 1.

[Zwagoner3]

I have been stuck at .875 for 4 days now hoping it would go back to 1. Ally logs show no reason to be at .875. That's why I'm so confused as what could be wrong.

[serx7]

Just b/c your logs are clear w/ DAM at 0.875 doesn't necessarily mean your car -should- be able to achieve/maintain DAM = 1, while still having a reasonable knock safety margin.

 

Do you know for sure that immediately after an ECU reset, your DAM defaults to an initial value of 0.625? If so, you can try the process below to artificially accelerate the DAM learning process.

 

Keep in mind that if your car really should -not- be running DAM = 1 (due to mechanical, tune, fuel or other issues), doing this will accentuate the problem, which of course isn't such a good thing: Warm up the car, then shut it off, reset the ECU, start it up again, gently drive to an open road, get into 3rd or 4th gear, bring revs to around 2500 rpm then apply throttle such that the car makes a few psi (~4-5 or so) without the revs increasing much (a hill or I guess left foot braking would help in this regard). You should see DAM increase within a few seconds, and assuming nothing else goes wrong during that process, your DAM will probably hit 1. As I alluded to earlier though, this isn't a good idea if your car/tune really shouldn't be running DAM = 1 given current conditions.

[serx7]

And FWIW, IMO if your car threw a misfire code before as you mentioned in your OP, and it isn't running smoothly during cruise and smells of gas moreso than 'reasonable' for a car w/ your flow mods, you should probably be focusing on getting those things straightened out before tinkering around w/ other things and going WOT.

[Zwagoner3]

I reset my Ecu, dam went to 1 right away. Drove about 12 miles home on the highway, hit about 12 psi in 3rd around 4k rpms and cruised the rest of the way home, no fine knock learning, no knock and dam stayed at 1. I am logging my whole drives though. I will log going to work tomorrow as well. I'm wondering if maybe its over fueling itself and causing it to have problems.

[Zwagoner3]

It's just trouble shooting this is the real PITA right now. I'm wondering if maybe I should invest in a wideband o2 and check my current o2.

[Zwagoner3]

Since the ECU reset everything has been fine until today. DAM is still at 1, but I got another -12 Feedback Knock and fine knock is starting to be a constant thing. I've been logging my whole drives and I tried to slim these 2 logs down as much as I could. They still might be a little long, but here they are.

 

https://docs.google.com/spreadsheets/d/1tHMRWglzYi0XCPw2pEyl-0Dbg5jhhZKZnYWbcA0E3ng/edit#gid=1190515919

 

https://docs.google.com/spreadsheets/d/19rOmIUcusznbCUk5B-uwi1Onu5v8PrCpa7KoicwLriQ/edit#gid=1310826063