Where's the BOOST? (with logs and an angry goose)

[LightMediumOBXT]

I'm trying to get my 2006 OBXT in sound mechanical condition before doing some upgrades and getting a pro tune. For some reason, I'm only getting about 8-9psi of boost. I've repaired and reinforced my intercooler and replaced several suspect vacuum hoses. As far as I can tell, I don't have any significant boost leaks. I pressurized the manifold via the signal hose that goes from the blue T to the bypass valve. I hear a slight hiss that I *think* is coming from the hose that goes from the boost controller to the turbo, but it's under the manifold, so I can't say for sure. There is a junction between a 6mm and 3mm (I think) hose under there. Wherever it is, it's a minor leak - it takes about 10 seconds for 3psi to leak from the system.

 

Another strange thing, but I don't think it affects boost, is the evap purge valve. It starts moaning like an angry goose when the system hits about 4psi.

 

So, my questions are...

 

1. Am I pressurizing the manifold correctly, via the hose that goes from the blue T to the bypass valve?

2. Should I replace the evap purge valve?

3. Do the attached RomRaider logs tell anyone anything? Could be coincidence, but it seems like I'm actually getting more knock now that I've fixed my boost leaks.

 

Any advice/help you guys can provide would be greatly appreciated!

 

-Mike

romraiderlog_spirited_1.csv

romraiderlog_spirited_2.csv

romraiderlog_spirited_3.csv

romraiderlog_cruise_1.csv

romraiderlog_cruise_2.csv

[heiche]

angry goose comes free with every car, it's normal. i prefer doing a boost leak test with low pressure and dial down the pressure until the goose goes silent.

 

btw where did you cap off the intake? with low pressure test you can remove the big s shaped hose from the airbox and plug it with something, like a pvc cap or empty spray can.

 

if you didn't include it in your leak test, I might suspect your turbo inlet hose of having a rip where it clamps to the turbo.

 

also your iam is down to 0.500 and won't raise until the knocking issue is resolved. then you can move onto the low boost issue.

 

can you post an LV?

[LightMediumOBXT]

Hi Heiche, thanks! Good to know about the free goose, at least that's $35 I'm not spending right now. I used an aluminum canister (for flushing AC systems) to plug the S-shaped intake hose. I’ll probably make one with PVC and a valve stem soon.

 

That IAM of 0.5 is the first time I've seen that. It's been 1 across the board in all of my logs up until that one, and whatever the event was that caused it to appear, it must have happened while I was backing my car out of the garage. I have a very short blip of a log that I ran just to keep my computer awake before I pulled out of the driveway, and the IAM was 0.5 in that one too.

 

I’ll download Learning View and run it as soon as I get a chance today.

[LightMediumOBXT]

The Learning View looks clean. Does that suggest that the knocks aren't really knocks?

 

http://i304.photobucket.com/albums/nn164/lionseyeball/LearningView_SS_6-10-2015%2012%2038%2059%20PM.jpg

[heiche]

wow, everything is looking a lot better than it was last time. IAM is back up to 1.000, and no FLKC. Nice. I'd probably pull an occasional LV like that just to make sure it's not acting up.

[LightMediumOBXT]

Yeah, I'm not sure what's going on. The three I shared are the first set of logs I've run that show IAM at anything other than 1 - even in logs that showed an occasional knock, IAM stayed the same and FLKC had time to right itself back to 0 before anymore knocking happened.

 

Seems funny that there would be a value in the Boost Error field at idle. Could that be because the car was tuned at sea level and now I'm at 902ft?

 

Do you have any theories on the lack of boost? Bypass Valve stuck recirculating maybe?

[doobaruGT]

Just throwing this out there as I'm only speculating and don't know much in the way of tuning (also on vacation and trying look at this on my phone)

 

Why is your WGDC at 90% at lower rpm's? Something seems up there.

 

Also, I didn't actually see boost on the few tables I looked at. I just noticed boost error. Did I miss something?

 

 

Sent from my iPhone using Tapatalk

[serx7]

OP:

Was the log you posted w/ IAM at 0.5, taken shortly after an ECU reset? I pulled up the Cobb "Installed Stock Mode" map for the 05 LGT/OBXT, and see that DAM Reset (default) = 0.5, so if you had reset the ECU, IAM would start at 0.5.

 

doobaruGT:

In the Cobb "Installed Stock Mode" map, WGDC Low and High are both specified at 90% at 2250 rpm when Throttle Position >= 95.2%. WGDC Low tapers to 56.80% by 2400 while WGDC High tapers to 63.80% by 2400. I think the high WGDC in his logs in the 2000-2300 RPM range are expected. OP's log has Manifold Absolute Pressure, but not Manifold Relative Pressure.

[LightMediumOBXT]

Thanks for chiming in, Doobaru.

 

Hey serx7, yeah, it was immediately after the car had been sitting for about three days without the battery connected, so that makes sense. It's a bit of a relief, I guess, because it's always been at 1. I thought I had made things worse somehow

 

My WGDC in the logs above seems to mostly dance just below WGD Max. I understood that as the ECU seeing boost error and trying to pinch off the waste gate. It doesn't improve, so it eventually goes all the way up to WGD Max and continues to fluctuate right around maximum.

 

Now I just need to figure out why I'm seeing so much boost error, and why there's some knocking happening. Could it be that the by-pass valve isn't closing? I guess I should pull it off and look at it, but I don't have another gasket.

 

Thanks for your advice!

[LightMediumOBXT]

...and all I have in the logs is Manifold Absolute Pressure. Atmospheric pressure is 14.22, but I don't see how that relates with MAP reading to get what I'm seeing on my boost gauge (-18 at idle, to about 8-9 at peak boost). When I try to log the calculated fields, I get a header errors flashing in the status bar in RomRaider and it won't log anything. I get that with several of the fields, need to do some digging into the cause. Maybe I'm missing some configuration files somewhere.

[serx7]

How much driving was done b/n when you reconnected the battery and took the LV? The AF Learning 1A trim will usually settle in pretty quickly once the car's warmed up and you've idled for a while, but the B, C, D trims can take a while depending on your driving style and driving conditions. I try to accelerate the settling in of the higher trims by throwing MAF g/s and the Closed Loop switch on my AccessPort's live display, then while on the highway dance throttle input around to let the car run for somewhat decent distances in each of the corresponding airflow regions while keeping the Closed Loop switch at the On value.

 

Turbodynamics will drive WGDC up/down based on Boost Error. In your case since you seem to not be hitting target boost, WGDC will be driven close to the WGDC Max value in an attempt to hit target.

 

The Feedback Knock I see in your 1st log (the one that appears to be part throttle acceleration through 3 gears), seems to occur about 1 sec after each upshift. Might be shift knock. It looks almost identical to my part throttle logs when I was dealing w/ a pesky shift knock issue a little ways back.

[heiche]

also you might want to trace your small hoses from the wastegate as far as you can. sometimes those can crack or split and affect boost control.

[LightMediumOBXT]

I'll check those hoses.

 

Pretty much all of the driving that was done since the ECU reset is accounted for in the "spirited" logs. The IAM starts out at 0.5 in the first log, and by the time I started the second log (probably only 60 seconds after stopping the first log), IAM was back up to 1 and it's been there since.

 

Some of the AF Learning values fall into the category of things I'm not able to log because of that header issue. Should I be concerned about my AFR fluctuating between 11.02 (the leanest the stock O2 sensor can detect, afaik) and 20.44, inversely proportional to Throttle Opening Angle?

 

It looks like the knock I see in my other logs also corresponds with shifting. I may have a worn transmission mount, would that be picked up by the knock sensor?

 

So many questions Thanks again!

[heiche]

I'll check those hoses.

 

Pretty much all of the driving that was done since the ECU reset is accounted for in the "spirited" logs. The IAM starts out at 0.5 in the first log, and by the time I started the second log (probably only 60 seconds after stopping the first log), IAM was back up to 1 and it's been there since.

 

Some of the AF Learning values fall into the category of things I'm not able to log because of that header issue. Should I be concerned about my AFR fluctuating between 11.02 (the leanest the stock O2 sensor can detect, afaik) and 20.44, inversely proportional to Throttle Opening Angle?

 

It looks like the knock I see in my other logs also corresponds with shifting. I may have a worn transmission mount, would that be picked up by the knock sensor?

 

So many questions Thanks again!

 

Yes on everything

 

Don't worry about the AFR values of 11 and 20 too much. They are the stock sensor limits. 20 shows up every time you decel. 11 at WOT isn't alarming, it's just a tad rich for WOT depending on who you ask, but it's the limit of the stock sensor so it's more like "Less than or equal to 11".

 

False knock is too easy to induce... bad mounts maybe, loose heat shields, anything rattling really. one guy even had a pebble rattling around a little cavity on top of the motor near the knock sensor

[LightMediumOBXT]

Ha! I did drop the bolt that holds the boost controller to the bracket somewhere down there... that bastard vanished. I searched for 20 minutes, probed blindly with a magnet... nothing.

 

I got the car used, and it had the bottom end replaced. They routed the vacuum hoses wrong when they put it back together. That makes me wonder now if the hose that's supposed to have the restrictor pill in it was replaced with a normal hose. Sounds like that could be a cause for the low boost levels. I'll check that too.

[LightMediumOBXT]

Look Ma! Shiny new (thin, weak, restrictor pill-less) vacuum hose!

 

http://i304.photobucket.com/albums/nn164/lionseyeball/boostControlHoses.jpg

[LightMediumOBXT]

I took the hoses off the reducer and T just to make sure they aren't some kind of fancy new fitting that has the restrictor built in. They're not. They're actually really crappy non-barbed plastic fittings. The perpendicular port on the T is even bent a little to the left. What's up with the reducer? Is that normal?

[doobaruGT]

Problem solved?

 

 

Sent from my iPhone using Tapatalk

[LightMediumOBXT]

I'm not sure yet but, from what I've read here on the forums, leaving out the restrictor pill will cause boost to be about 4-6psi lower than it should be. I just need to get a new hose assembly and install it to find out for sure. I'll let you know what happens!

[LightMediumOBXT]

Well I'll be... it seems we've found the BOOST! I don't have the new line with the restrictor pill in it yet - one local dealership doesn't have it in stock, and the other local dealership doesn't seem to know what it is. So I went to my local independent hardware store and picked up a 0.035" mig welding tip and crammed it in the line. According to this table, the orifice is supposed to be 0.04, so I'm .005" on the small side, which should lead to over-boost. And it does. I just logged a 1-3rd gear WOT run (watching the boost gauge out of the corner of my eye) and it's hitting 15psi. The worst period of over-boost lasted about 0.8 seconds and peaked at about -5psi for short time. I need to run another log because I missed some critical parameters (like boost).

 

I'll post updates when I have a new log, and log again when I get the OEM hose assembly. Thanks for all of your advice everyone!

[heiche]

nice work my friend, you made that look easy!

and welcome to the forum

[LightMediumOBXT]

Thanks Heichi! I'm hoping to log a run today, work permitting.