StkmltS

I stuck the camera in there and poked around a bit, but there isn't much room in there to move it around much. I did get a good view of the piston though. Navigating the camera consists of twisting and pushing it's [uSB] cord, so not nearly as maneuverable as the ones they use in spy movies. I could try pushing the camera through the spark plug hole backwards, but with the cord doubled-back like that it's a tight squeeze and I'm terrified that it would get wedged in there and I'd have to perform heart surgery to get it out. Did they give you a break-in tune or are you just taking it easy on your stock tune?

I was thinking the same thing until I came to the brilliant realization that I can't see the exhaust valves from the intake side of the motor. The best I'm hoping for is to find enough room on the back side of the valves for the camera to move around just enough to be able to look past the open valves and see part of the cylinder wall. I don't think the valve opens far enough to get the camera past it.

I'm also removing the rods, dividers, motors, and sensors. The head keeps staring at me saying "just pry me open a little bit... come on, you know you want to see what's inside." It's so hard not just going in for a little peek. Buying new gaskets (and studs?) would be enough to keep me from getting out of debt this month so it'll just have to wait.

Well, I got the intake manifold completely removed in only 1hr 31min, so that's a small victory. My wife came home earlier than I expected so car time was cut short and I only got one TGV partially gutted. The gaskets between the TGVs and heads showed no signs of leaking. So new gaskets probably won't fix my misfire (no big surprise).

I'm putting in new TGV>head gaskets tonight and deleting the flappers while I'm in there.

It looks like there are several people who've gone through some pretty extensive (expensive) trial-and-error stuff trying to banish the stumble, and from what I've read on here and on NASIOC it seems like replacing the OEM fuel pressure regulator from an '07 or older STI fixes the stumble. Here's one of the easy-to-read threads. Adding an inline filter or extending the lines sounds like it would be a cheaper solution to accomplish the same thing, it's just not as "correct" as replacing the FPR because it doesn't address the root cause of the stumble. I'm not correcting what you said, I'm just mentioning it for the good of the generic internet population. The stumble isn't doing any damage to the motor, so it really just comes down to how much #BecauseRacecar dedication you have... and how much extra cash you have to spend on replacing something that isn't actually broken.

I've always wondered what those are for... are they instead of, or in addition to the orange o-rings? When I installed new ones about a year ago they were orange. The old ones were also orange, but noticeably smaller. From the original post "The part number for the new o-rings is #14035AA492" Per RockAuto.com the p/n for the TB o-ring is 16175AA331 (or 16175AA330 ?).

I feel like I may be on to something here... I combined all of the data from 9 recent logs, trying to find some correlation between my misfire and anything else, and it's obvious that I'm missing data for quite a few values that I think should be coming from the MAF sensor. For those who datalog: Do you have data for any of these values? AFR = 11.2, 12.0, 12.8, 13.5, 14.3, 15.1, 15.9, 16.6, 17.4, 18.2, 19.0, 19.7, 20.5 My combined log has 85,537 rows of data, and none of them contain data for any of the above AFR values. The chart should explain why I'm asking.

Checking the compression was one of the first things I did. The numbers were consistent across all four cylinders, but they were extremely low; I'm saying because I tested the motor when it was cold. Who knows, maybe all of my valves are jacked and cyl#2 is the only one mad at me enough to misfire. Now that I'm [very] familiar with my engine bay it would probably be wise to do another compression test with the motor hot. When I tested it last January I was concerned that I wouldn't be able to pull the plugs very quickly and I didn't want to test each cylinder at a different temp. Everyone would probably agree that I should have pulled my motor a long time ago to see exactly what's going on in there. I haven't done that yet because I right now I don't have the cash to fix whatever big problem I may discover (cracked piston, head job, etc), and I'm not about to pull the motor apart and put it back in without 100% fixing the problem. Hoping the motor doesn't go chug-a-chug-a-ka-boom before I'm ready, I decided to take the cheap (& frustrating) route and work my way through all of the $0-$200 potential fixes that I can imagine. I've only been spending money on things that would eventually get replaced anyways (except an injector), so the only thing I'm out is time and frustration. After my wife and I are out of debt (our goal is Christmas) I'll be able to save for a couple months, pull the motor, and pay cash to fix whatever the problem is. Getting out of debt sucks, but it'll feel great driving around in a beautiful 5-spd turbo wagon with a strong motor and no debt. Check out BtSSM (link in my sig). Even if you don't have an android phone it's worth buying an old one just to datalog.

Sounds like you're on the road to recovery. How did they/you diagnose the burnt valve? Keep me posted on how it runs after you get it all back together again.

I boro'd the cylinder but I couldn't see the walls because the mirror attachment is too crappy. All I could see was a normal looking piston. To be more precise, it only misfires under vacuum. It still occurs at high RPM when MPH=0, and I have a few logs where it sporadically showed up when MPH>0 (not a continuously rising count though). Maybe I can find a way to shove the borescope in the spark plug hole backwards > looking up at the valves. Attached image is just for amusement.

In Steve Urkel's voice "Did I say that?" The dichotomous emotions of one who's owned by a Subaru... I haven't seen the valves yet. When I had the IM off my OTG adapter was lost deep behind the steering column so I couldn't use my boroscope. At the time I didn't think to use the scope with my laptop. When I get around to deleting the TGV's I'll scope 'em out. Even then I'll only be able to see the valve stems, right? 1. Still misfires 2. Hard to tell, but it still sounds like it's there (FWIW the misfire was present before I replaced my clutch/FW goodies last winter) 3. The A/C doesn't affect the misfire either way How does the ECU determine the roughness count? It's probably worth mentioning that much of the time that I can hear and feel it misfiring, logging with BtSsm/RomRaider shows zero roughness.

What do you mean by 'drag the clutch'? Sent from inner space.

Sometimes it looks like that, but when the car isn't moving increasing the RPM doesn't help. It makes no sense, but it seems like an odd combination of RPM, speed, and manifold pressure. I did (from post 246): Measured valve clearances post-VJ: Cyl#2 intake: .007" (unchanged) Cyl#4 intake: .007" (unchanged) Cyl#2 exhaust: .014" (was .008") Cyl#4 exhaust: .013" (was .012") Don't say the R-word! Neither engine temp nor air temp increases or decreases the severity of my misfire. It happens, always.

My OTG cable broke a couple weeks ago so I haven't logging in a while. I wish I had data from yesterday. My new cable will be here this weekend with my gaskets. Attached is a scatter plot from my last relevant log with significant time at idle. Typically the roughness count doesn't go above 25, I can't remember the last time that it went above 50.

Puzzle of the day: Twice yesterday, for about 5 seconds of idling @ each stop, I heard and felt NO misfires. For the very first time since the problem started, I briefly felt zero misfires. What in the wide wide world of sports has the ability to cause/allow the misfire to temporarily stop? I ordered new gaskets and I'm going to delete my TGVs sometime in the next few weeks.

Yeah, and easy TGV deletes. Haha I didn't even notice that, totally unintentional.

Every once in a while life hands you humbling situations to keep you grounded. The negative lead connecting to the battery was dirty. 'Er IU'/Voltage/starting problem resolved. I think I'm going to have my heads inspected/machined/cleaned/rebuilt as a separate project independent of getting a new SB. If my a bad valve is causing my misfire then my problem would be solved and I'd be a happy camper. If I still end up needing a full build then who cares, the heads would have gotten rebuilt anyways. Other than a catastrophic turbo failure I don't see any reason not to just do the heads. The best part is that it'll be easier to get my wife to sign off on it (because less $$$) , AND I can get my heads done in about 1/3 of the time It'll would take me to save up for a new block. This weekend I found out my friend has an '09 LGT that appears to be stage 2. The previous owner had all of the work done and my friend isn't very clear about what's been done to it. Driving it was a baaaaad idea because now mine feels so slow. I'm dying to see what my car would be like without a misfire.

I left the battery in the car but the negative terminal was disconnected the whole time. After charging it overnight I still had to jump it this morning. It didn't even have enough power for the key fob to unlock the car. When I got to work and locked the car the alarm chirp was barely audible. I'm gonna take it back to Pep Boys and have it tested and hopefully replaced. There's no reason a 1-year old Bosch battery should act like this.

The battery was measuring around 11.6 volts so I connected a portable jump starter (instead of the AC charger) and it started immediately. My battery is fairly new so I wonder why the voltage drops so much after being unused for only a week. Sent from inner space.

I just finished changing my timing belt, water pump, thermostat, and pulleys. I gave myself a little break from my general frustration with the car by painting the TB cover. Thoughts? The battery hasn't been connected for about a week and its refusing to start and showing the "ER IU" error again. Maybe when it isn't connected for a long period of time the IU fully drains and needs a little time to juice back up. http://images.tapatalk-cdn.com/15/11/05/91e5e03f4eb751c2ac217eb83987e7e7.jpg Sent from inner space.

How much vacuum do you see when the motor is running? Hahah jk If you're getting zero vacuum it must be a huge leak. Stupid question... Is your throttle body to IC hose attached?

See attached. Also, see here or here.

All in good time... all in good time. My wife and I will be out of debt (excluding the house) around Christmas, so my plan is to save up for a full-bore (get it?) #ynansb project next spring/summer. Thanks for the words of encouragement. This car was supposed to be a reliable replacement for my dying DD and it's grown into a project that's a little bigger than what I thought I was signing up for. It's been fun though and I'm happy for everything I've learned along the way.

MAF scaling is fun Finally I can do something to my car that makes a noticeable difference!