Just another misfire/rough idle thread...

[xt2005bonbon]

Let us know how it goes. I am contemplating on changing that hose too.

[Max Capacity]

If the engine has been on the stock MAP for all this time...I'll bet you have burnt valves. The leak down test show's that.

[StkmltS]

If the engine has been on the stock MAP for all this time...I'll bet you have burnt valves. The leak down test show's that.

Agreed. My harbor freight tester isn't as accurate as an Insert Brand Name tester, but even so I shouldn't be seeing leakage numbers anywhere close to 20%. If the new inlet doesn't fix the misfire the heads will get rebuilt as part of my #YNANSB project. Even if the new inlet does fix the problem I'll still probably rebuild the heads in a few years.

 

The car is 10 years old, but the interior and exterior are still in superb shape and IMO it's worth putting money into the motor to keep the car on the road.

[xt2005bonbon]

Then if you rebuild the heads, at least you'll also be able to inspect the cylinder walls.

[StkmltS]

Tonight I removed the intake manifold and installed my new inlet. Everything is back together but when I try to start the car it makes a machine gun sound and the motor doesn't turn over. I went over everything three times but somehow I must have missed a connector somewhere that I unplugged to take off the stupid idiot intake manifold. It's too late to rip apart again tonight so I'll just have to hope for more car time this weekend. Bummer.

 

Sent from inner space.

[heiche]

Battery low?

[StkmltS]

The odometer displayed "ER IU" (integrated body until) so I unplugged the battery for a few minutes and all is well now.

 

Unfortunately the engine is still audibly misfiring. I won't know if it improved any or not until I take it down off the stands and drive it around for awhile.

 

Sent from inner space.

[heiche]

Could that error AND the misfire be something like this? http://legacygt.com/forums/showthread.php/new-used-ecu-going-my-lgt-208951.html?t=208951

 

A bit of a stretch but who knows?

[StkmltS]

I think I'd rather replace the motor than deal with that nightmare.

 

On a bad note, it did it again this morning when the motor stalled at a stop sign on my street. Resetting the ECU multiple times didn't help, but physically disconnecting the battery fixed it on the first try. Hopefully it's just a low-ish battery problem and my drive to work was enough to fully charge it.

[xt2005bonbon]

Then, monitor at least your voltage. You should see between 13.7-14.4V when the car is running. A fully charged battery should be around 12.6V I think. If the voltage is the 11s, then no good.

[StkmltS]

I haven't seen the ER IU error since two days ago. It must have been a low battery.

 

I think I created a new vacuum leak when i replaced my turbo inlet.

Check out these LVs from the last 50ish miles of driving. The car idles worse than ever and it stalls at every stop and even when 45mph + clutch in.

 

Also, yesterday my wife found a 12mm (head) bolt on the garage floor. It's definitely a Subaru bolt. Other than for the TMIC and alternator I don't remember taking out very many 12mm bolts when I removed the intake manifold. Maybe it's from under the small coolant reservoir in front of the turbo...

Edited October 7, 2015 by StkmltS

[xt2005bonbon]

where is the LV?

[StkmltS]

where is the LV?

Fixed it.

[xt2005bonbon]

wait, don't you have btssm?

 

in any case, yeah, running super lean. Must have a huge vacuum leak somewhere, but interestingly does not show up at idle..

[StkmltS]

wait, don't you have btssm?

 

in any case, yeah, running super lean. Must have a huge vacuum leak somewhere, but interestingly does not show up at idle..

It should show up at idle because it's DEFINITELY a problem at idle.

 

My OTG adapter fell into the abyss behind the steering column

I'll probably open up the dash and dig it out this weekend. I've been tossing around the idea of routing my OBDII extension cable to the other side of the center console so I'll probably do that too.

[xt2005bonbon]

Man, good job on not giving up... Cause so far, you definitely have NOT been enjoying your car to its full potential. I hope you will do soon.

[StkmltS]

Thanks for the word of encouragement. I'm fortunate for being able to enjoy working on my cars just for the sake of learning and saving $.

 

The leftover bolt from my exploratory adventure under the intake manifold was one of the two bolts for the driver's side IC bracket > manifold. I dropped it when I was putting everything back together and I wrote it off as a loss after a few minutes of fruitless searching.

 

Either the vacuum hose on my BPV popped off or I forgot to put it back on. I don't have a zip tie on it because of how frequently I've been removing the IC. After putting the hose back on my LVs are back to where they should(n't) be and the motor idles like a semi-normal car again.

 

A couple days ago I disabled the cyl#2 misfire code (cruise control works!) and I bumped up my minimum idle speed to 825.

 

Looking back from ahead (huh?) buying that turbo inlet is probably the last chunk of change that I'll be able to spend on my car this year. My wife's minivan just started leaking coolant so I may have to change a head gasket soon.

[xt2005bonbon]

so how does your latest LV look like?

[StkmltS]

so how does your latest LV look like?

[StkmltS]

Begin damage control mode in 5... 4... 3...

 

I'm moving forward with this car expecting that one day I'll be driving down the road and the motor will go snap-crackle-pop. I'll have it towed home and I'll whip out my build list spreadsheet and send out the invitations to my #ynansb build party. Maybe it'll be this winter, maybe it'll be three years from now. Either way I'm emotionally ready for my car to tell me "it's not you it's me".

 

Until then I'm just going to drive it easy and keep it clean. I'd like to maximize the time between now and boomsday, so I'm going to play around with the tuning and try to squeeze as much life (not horsepower) out if the engine as possible. Simple things, nothing crazy. My goal is to extend the life of my presumed-damaged motor. I know this isn't the right way to fix a car, but with my current budget it's my only realistic option other than selling the car (gasp!)

 

So...

The car is miserable after an ECU reset, so dealing with the LVs is my first priority. From what I've read I think I need to change my MAF scaling. Is that the most correct way to deal with my learned values? (other than fixing the root cause).

 

The attached pic is just to show that I'm capable of doing what I'm talking about. The x-axis is MAF sensor Volts, Correction % is LTFT+STFT, Mean (and Mode) is the average (and mode) % change for all values that fall within their respective cells in my ROM's MAF scaling table.

[The method I used is listed as a resource in post #1]

Edited October 12, 2015 by StkmltS

[Klesseca]

I've got a couple questions maybe you guys on the forum can answer because it seems like other people have had similar issues. Little background 2006 lgt currently 173k, turbo blew at 145k due to a clogged banjo bolt. Due to the fact I didn't want further issues, I replaced turbo, intercooler, oil cooler, and ran AN stainless turbo oil feed lines, "flushed" oil 3 times, (3 oil changes within 100 miles). Car ran great for 25k, and now more issues. It started with a loss of power on the top end right around 4k rpms it would just stop pulling, followed by what sounds like a backfire through the intake at this rpm. Shortly after I threw a cyld 2 misfire code, I went through the usual checks, and swapped injectors, code seemed to follow injector. A day or so later I noticed that the rpms at idle dropped way off (500 rpms) and had a terribly rough idle. It always reflashed a check engine light after sitting idle (stopped at a red light, then takin off) for the misfire code, which led me more to believe it was leaking injectors(loading up the cylinder then missing once put under power or increased rpm) I sent the injectors out to get rebuilt because I figured if I had an issue with one the other ones were only a matter of time. I got the injectors back and thought wow I really miss my lgt and can't wait to drive it again, put the injectors in and wala! ....same issue. Back to the drawing board. I figured from a bad injector I fouled the plug, so she got all new oem plugs. Same issue...I also figured if I was dumping raw fuel into exhaust I may have burnt up an o2 sensor. My scan tool was reading 2.8v on the upstream sensor. To my knowledge an o2 sensor shouldn't read more then 1.0v? So I replaced with a bosch o2 sensor. Still have a rough idle and no power on top end. I also noticed the upstream sensor is still reading 2.6v at idle. After replacing pcv valve, plugs, injectors and 02 sensor I cleared code. Drove maybe 5/10th of a mile and instantry threw codes. Except, it threw a misfire code for every cylinder..... while that kind of confused me I cleared codes again and drove around with only the #2 cylinder misfire code coming back. I replaced the #2 cylinder coil and thought that had to be the problem. Still same issue. Due to the fact that it threw a code for every cylinder I thought it has to be somthing that affects all cylinders. Next up was checking fuel pressure, off the regulator fuel pressure seemed fine, maybe a little high but I don't think that would cause this issue, reading 40-41 psi at idle, and 50-57 under load(driving car), diconnected vaccum line to regulator and fuel pressure increased. When I did the turbo at 145k I replaced all intake gaskets. I'm stumped, is there anything else I should be checking before I do a leakdown and compression test? Thanks in advance for any help

[heiche]

Begin damage control mode in 5... 4... 3...

 

I'm moving forward with this car expecting that one day I'll be driving down the road and the motor will go snap-crackle-pop. I'll have it towed home and I'll whip out my build list spreadsheet and send out the invitations to my #ynansb build party. Maybe it'll be this winter, maybe it'll be three years from now. Either way I'm emotionally ready for my car to tell me "it's not you it's me".

 

Until then I'm just going to drive it easy and keep it clean. I'd like to maximize the time between now and boomsday, so I'm going to play around with the tuning and try to squeeze as much life (not horsepower) out if the engine as possible. Simple things, nothing crazy. My goal is to extend the life of my presumed-damaged motor. I know this isn't the right way to fix a car, but with my current budget it's my only realistic option other than selling the car (gasp!)

 

So...

The car is miserable after an ECU reset, so dealing with the LVs is my first priority. From what I've read I think I need to change my MAF scaling. Is that the most correct way to deal with my learned values? (other than fixing the root cause).

 

The attached pic is just to show that I'm capable of doing what I'm talking about. The x-axis is MAF sensor Volts, Correction % is LTFT+STFT, Mean (and Mode) is the average (and mode) % change for all values that fall within their respective cells in my ROM's MAF scaling table.

[The method I used is listed as a resource in post #1]

 

I like it! Yeah, fatten up the MAF curve and repeat (gather data, plot, lower an eyebrow at it, and tweak if necessary).

[StkmltS]

I've got a couple questions maybe you guys on the forum can answer because it seems like other people have had similar issues. Little background 2006 lgt currently 173k, turbo blew at 145k due to a clogged banjo bolt. Due to the fact I didn't want further issues, I replaced turbo, intercooler, oil cooler, and ran AN stainless turbo oil feed lines, "flushed" oil 3 times, (3 oil changes within 100 miles). Car ran great for 25k, and now more issues. It started with a loss of power on the top end right around 4k rpms it would just stop pulling, followed by what sounds like a backfire through the intake at this rpm. Shortly after I threw a cyld 2 misfire code, I went through the usual checks, and swapped injectors, code seemed to follow injector. A day or so later I noticed that the rpms at idle dropped way off (500 rpms) and had a terribly rough idle. It always reflashed a check engine light after sitting idle (stopped at a red light, then takin off) for the misfire code, which led me more to believe it was leaking injectors(loading up the cylinder then missing once put under power or increased rpm) I sent the injectors out to get rebuilt because I figured if I had an issue with one the other ones were only a matter of time. I got the injectors back and thought wow I really miss my lgt and can't wait to drive it again, put the injectors in and wala! ....same issue. Back to the drawing board. I figured from a bad injector I fouled the plug, so she got all new oem plugs. Same issue...I also figured if I was dumping raw fuel into exhaust I may have burnt up an o2 sensor. My scan tool was reading 2.8v on the upstream sensor. To my knowledge an o2 sensor shouldn't read more then 1.0v? So I replaced with a bosch o2 sensor. Still have a rough idle and no power on top end. I also noticed the upstream sensor is still reading 2.6v at idle. After replacing pcv valve, plugs, injectors and 02 sensor I cleared code. Drove maybe 5/10th of a mile and instantry threw codes. Except, it threw a misfire code for every cylinder..... while that kind of confused me I cleared codes again and drove around with only the #2 cylinder misfire code coming back. I replaced the #2 cylinder coil and thought that had to be the problem. Still same issue. Due to the fact that it threw a code for every cylinder I thought it has to be somthing that affects all cylinders. Next up was checking fuel pressure, off the regulator fuel pressure seemed fine, maybe a little high but I don't think that would cause this issue, reading 40-41 psi at idle, and 50-57 under load(driving car), diconnected vaccum line to regulator and fuel pressure increased. When I did the turbo at 145k I replaced all intake gaskets. I'm stumped, is there anything else I should be checking before I do a leakdown and compression test? Thanks in advance for any help

 

Have you done the work you mentioned yourself or did a shop do it? There's no right or wrong answer here, it's just sometimes helpful to know if what you're saying was done is coming from the person who did the work or not. Know what I mean? Either way it sounds like you know what you're talking about.

 

 

• When your turbo blew the first time was the oil pan inspected/cleaned? If not, (worst case scenario) there could have been some metal fragments from your blown turbo in the pan that made their way through your motor after you replaced the turbo. What did your turbo look like when it bit the dust?
  
• When the motor is running are the odd noises constant? It could just be the sounds from your misfires, or it could be your turbo wobbling around inside the housing. A short video or sound clip may be helpful. I've never heard the terrifying "chain in a lawnmower" turbo noise people talk about, but I'm pretty familiar with the noises caused by a misfire.
  
• If you have the equipment to do a leakdown/compression test I think that should be your next move.
  

[Klesseca]

All the work was done myself, the pan was not cleaned, I had no means to drop the front crossmembe to get the pan down as I don't have a lift, hence the reason I "flushed" it like I did, no metal came out of oil, as I ran it through a magnetic strainer to check. Also there was no sign of metal fragments on the plenam side of the intercooler. Odd noise is not constant, only once the power drops off that's why it's leading me to believe it's a backfire, as in getting too much air almost, be a use the more you lay into it, the worse it gets. I had more of an "angry cat" noise when my turbo blew. I can try to get a video clip this afternoon. I do have a leakdown and compression tester so I will do that, I just wanted to make sure I covered all the "easy" bases first. Thanks

[heiche]

Another relatively easy test is a boost leak test. Perhaps this latest issue is just a boost leak?

 

Also just fyi the front one is a wideband afr sensor so you can't monitor voltage the conventional way. The rear O2 sensor (post cat) is conventional though.