StkmltS

I have the same issue, it's been parked since March, it started when changed the spark plugs with Denso iridium, throwing codes p0303 and p0304, returned back to old spark plugs, recheck the gap, changed the spark plugs, new set of wires, change the ignition coil, clean the fuel injectors, check the pressure in fuel lines, change the throttle body, change the rear O2 sensor, finally I changed the MAF, forgot to mention that I changed the fuel filter too, we thought the cause was the fuel as the car was idling fine with fuel aditive till reached the point of nothing help...with all of that still have misfire on cylender 3 and 4, both didnt move...still didnt get the time to do a compression test...probably this week...I am thinking in draining the fuel tank and add a new fuel? if didnt help will take it to dealer...

Welcome to the fourm!

That's really strange that it started when you changed spark plugs and it didn't go away when you put the old plugs back in. Maybe your problem has something to do with how they're sealing, not the actual plugs themselves.

Have you inspected (and cleaned) your two camshaft position sensors and your crank position sensor?

Understood. New turbo is sitting here waiting to go in. The car is on stands and the engine is not being run until I'm sure I've saved it. I am going to drop and inspect/clean the pan, then run two more complete oil changes though it (replace turbo/oil line, clean the OCVs and oil lines, do an oil change, run the engine to full op temp, do another oil change, then start driving it and cross my fingers. I'm hopeful I can save the engine, but also not going to be too surprised if the engine goes south vary soon. I'm going to look at installing an oil pressure gauge to keep an eye on things for now.

 

Thanks!

You should make a turbo replacement video for Youtube like the one you did for the clutch replacement. Watching your clutch video a few times beforehand is probably the biggest reason I was able to successfully change my clutch without having anyone there to help. I'm sure the world would be a better place if you made a similar one for replacing a turbo.

My DD is back on the road so the LGT is back inside the garage patiently waiting for my attention.

I still haven't done the leak-down test... after that I'll take off the intake manifold and try to locate my vacuum leak.

Just a nugget of interesting info... the past few times that my CEL turned on was exactly between shifts, somewhere in the ballpark of 4.5-6k rpm (nowhere near idle).

Looks like they are the same according to this diagram - see part #6

I guess I should have looked it up before asking... thanks for the info.

My car seems to have the same symptoms yours does with the very erratic yet stubbornly persistent misfire. I've logged some data via the BtSsm app and it confirms what I feel, which is also what you describe; the misfires vary in frequency seemingly at random. I'm subscribing to this thread, hoping that I can learn from what you figure out with your car.

Good luck, hopefully you'll solve your problem quicker than I am.

On our EJ255's are the bank1/bank2 camshaft position sensors interchangeable?

Just the digital version via the torque app, so I know I'm not seeing everything that's going on in real-time.

I know it's not as good as an AP, but I log everything via torque... should I dig through the data and look for something in the vacuum/boost data?

After the car warms up you would think the issue would be consistent. What was the car doing that last 5 minutes? I assume you shut the car off when you got home. Rough start? Stutter?

The last 5 minutes prior to turning it off was stop/go traffic with a couple red lights and stop signs.

When I got home I turned it off a few seconds after completely stopping the car, the idle was smooth (but with a barely noticeable misfire).

When I started it back up after dinner it was immediately idling rough. When I'm accelerating while the idle is acting up it does seem to stutter slightly at about 3k rpm.

The soap is for keeping the IC clean. Though now I just pressure wash the entire engine with boiling industrial degreaser and only a light misting of soap on the IC for protection.

Also running a garden hose through the throttle body is a great way to get that deep engine clean; forget Chemtool, Seafoam, etc...

For future readers: His first tip, and possibly his second tip also, is why people sometimes say "you can't believe everything on the internet".

If it is a burned valve, it would come and go with temperature as the block warms and cools. I have seen that before.

 

I had a cracked ringland. It would pass compression testing it finally failed one and then a leakdown test confirmed it. I compression tested once I knew something was up. I had a cyl 4 misfire. It wouldn't log any misfires when cruising and accelerating. Only at idle. And even then there were some times it wouldn't at all. I understand why you're asking. And yes it is logical, but if you think what happens inside the cylinder walls, that's all pretty violent stuff going on. And when it comes to cars and car repairs always expect the unexpected.

My issues don't seem to be correlated with engine temp at all.

I've experienced smooth and rough idles in cold weather with both cold and warm starts, and I've experienced smooth and rough idles in warm weather with both cold and warm starts. As best as I can tell the engine temp has little to zero affect on the symptoms.

When it's in a bad mood and idling rough it is always also idling low, like between 400-700 rpm. It's almost like the ECU isn't reading the idle properly. Don't get too excited just yet, because even when its idling properly the misfire is still present.

Here's what kills me. Yesterday my commute to/from work was as smooth as butter, like everything in the world was as it should be. Then 45 minutes after I got home, my 5-min drive to scouts (I'm a leader) was horrible. What gives?

Wouldn't a mechanical problem be constant? (eg. burnt valves, ringland failure)

If I don't have to work next Saturday I'll try to finally get around to that leak down test.

try addin soap to da intercooler

I thought getting soap on my intercooler would cause problems?

If what you're saying is right, then I've been doing it wrong the whole time by not allowing soap to get on my intercooler and maybe the lack of soap actually caused this whole mess! Does the soap provide some kind of extra lubricating that regular engine oil doesn't do?

Your numbers for compression are almost 100 psi less than the minimum specified, a cold engine wont affect pressure that much. Did you unplug your fuel injectors first? spraying fuel in there will wash the oil off the cylinder walls creating a poor seal between cylinder wall and piston ring. DID YOU EVER RETEST COMPRESSION LIKE YOU SAID YOU WOULD? I SEE NO UPDATE ON THAT..

 

So, i have to ask, why you are continuing to chase #2 injector? Your diagnostic process, although very thorough, is only focusing one area. To have combustion you need good compression, good fuel, good spark, and air. You know you have good spark, and good fuel, so whats left? It couldnt be a lack of oxygen, that would require two fuct intake valves, if that were the case you would have a constant non stop misfire. You need to go back to compression test, those numbers sucked. see what i said above. disable the fuel system first.

 

Also you should consider ditching a compression test, and go straight to the leak down test. It will tell you whether your losing compression past intake or exhaust valves or piston rings. It will also tell you the percentage of leakage. I dont want to see anymore updates, that are not really an update because you are chasing the same shit. over and over and over again. If you cant leak down test the motor, then pay someone to do it.

 

 

 

 

 

My car had the same type of pattern of misfire. YOU NEED TO LEAKDOWN TEST

 

 

 

Your o2 sensor voltage is not actually a parameter that you should be watching, because your o2 sensor is in the downpipe, it monitors post catalyst ratios for emission control.. Air fuel ratio is controlled by the forward air fuel sensor, the one that is mounted in the exhaust manifold pipe before it bolts to the up pipe ( i am not talking about the egr sensor in the up pipe right before the turbo). Air fuel ratio sensors operate differently than an oxygen sensor, and unless you can hook up an amp probe to your phone you wont know what the amperage draw of that sensor is. Also, the o2 sensor voltage you're monitoring, it does not specifically measure each individual cylinder, so stop chasing that rabbit immediately.

 

You see your numbers indicating a lean, well yeah. The oxygen drawn into the cylinder is not burned. Therefore oxygen leaves the cylinder unburned. It acts like a 'slug of oxygen' running through the exhaust, of course youre going to see lean on the post cat sensor...

After I got past your attitude and scary formatting it looks like you actually have some good points.

1. I haven't done another compression test yet. I didn't unplug the injectors, but I did pull the fuel pump fuse and run the engine dry before doing the test.

2. To be totally honest, I've been chasing injector #2 because it's easy to get to. I work two jobs (60+ hrs) so that my wife can stay home with our kids, so whenever I'm home my family usually takes priority. Most weekends my car sits in the garage and doesn't even get a second glance. I'm trying to exhaust all of my easy and cheap options before moving on to the time-consuming ones.

3. You're right, I probably should do a leak-down test. See #2 for why I haven't done one yet. I've been documenting my progress (or rabbit chasing) on here because I like/need input, and also because my trial-and-error education may be helpful to someone else someday. If you think I'm an idiot or you just aren't interested in watching me solve the problem then unsubscribe from the thread. Let's not start an Internet fight.

4. If my bank 1 (front) O2 sensor is reading >2.6 volts that means my A/F ratio is lean. Right? It's just a data point worth mentioning. I should have been more clear and said "...at least one of my cylinders is running lean, I'm assuming it's #2."

So... should I do a leak-down test or not? :spin:

It'll probably get to that point, but wouldn't it be much simpler if I could narrow it down to something simple like a loose or exposed wire?

Does this roughness usually happen when the engine is cold, and go away when it's fully warmed up? If so, have you considered the TGV o-rings? (believe you swapped out the intake-to-head o-rings, but these are different). They are notorious for creating a vacuum leak when cold, then when things heat up, they start to seal better. The new replacement ones are much thicker and do a great job at sealing. Just a thought.

I wish it was that simple.

Cold, warm, hot, it doesn't seem to matter.

Thanks for your $.02 though.

Post #1 updated.

Summary: still not solved, checking the vacuum lines is next.

I received new o-rings in the mail on Friday. I'll put them on tomorrow even and see what happens. I'm not very confident that new o-rings will fix my problem, so....

By an amazing stroke of luck (and some praying) I stumbled on a used injector on ebay today. It was only $20 so I snagged it about as quickly as you can say holy-fuel-injector-batman! I should have it in my car by Friday.

Will the problem's legacy be vanquished, or will the turbo wagon still run with a stumble in it's step? Stay tuned for next weekend's long awaited finale. Same bat time, same bat channel.

Direct Metal Laser Sinterting is what you seek.

Or DMLM if you're a GE-type.

(article here with a pic of a 'printed' fuel nozzle)

Have you by chance happened to check out the harness for the injector for frays, cuts or pinching?

I haven't looked at it any closer than I needed to in order to remove the injector. The misfire started out in cyl#2 and moved when I swapped the injector with the one from cyl#1. If there was something wrong with a harness or wiring then I think swapping injectors wouldn't have caused the misfire to move.

Post #1 updated.

Soaking overnight in carb cleaner and running it through my ultrasonic (soaked in Lucas fuel treatment) for 20 minutes didn't fix it.

The o-ring kit I bough didn't have the right sized o-rings or pintle caps... so I don't know if that would solve it yet.

I'm getting close to just buying a new (used) injector.

In addition to tools here's what you'll need (assuming you're doing the flywheel):

• TP50 socket/bit to remove the flywheel (torx and torx+ aren't the same shape, so the "+" is very important. I got mine on amazon [ame=http://smile.amazon.com/gp/product/B000O846UI/ref=oh_aui_detailpage_o04_s00?ie=UTF8&psc=1]here[/ame])
  
• Flywheel (I reused the OEM torx+ bolts & the flywheel bearing)
  
• Friction plate (nothing else needed)
  
• Pressure plate (mine included new bolts)
  
• Throw-out bearing (not always necessary, but why not do it while you're in there?)
  
• Alignment tool (cheap-o plastic, should come with your kit)
  
• Grease for the driveshaft (people often argue about the type/brand)
  
• You'll probably also want/need a can of PB Blaster (brand) penetrating oil.
  
• Sticker for your window *optional, but generally agreed upon as an unproven performance enhancer*
  

About 450 miles ago I installed the Competition Clutch (brand) stock replacement clutch kit for '06-'14 WRX's / '05-'09 LGT's (this one) from RallySportDirect. Everything fit perfectly except the pressure plate slapped the dust cover on the underside of the tranny. The noise sounded like a thousand hornets destroying my transmission (vid

My new clutch insn't fully broken in yet but so far I'm very happy with it.

Oh yeah, and no engine codes or weird noises from the lightweight flywheel.

Maybe your satellite unit output is a "line out" instead of an "audio out"?

One of my older computers had both types of outputs and whenever I plugged my headphones into the wrong jack the volume would be super low.

I would not put binkies in there after you've run the fuel injectors through. Yuck!

 

Stick with a good toothbrush cleaning and soak in boiling water to disinfect, or those microwave cleaning cases they come in-

Think of a double-boiler... put the injectors in a small beaker-type glass jar, and fill that with the cleaning liquid. Place the glass jar in the center of the bath area and surround it with regular water so the machine can do its magic. The sound waves still work to clean whatever you put in the glass jar, you save $ by using less cleaning agent, and your ultrasonic doesn't come into contact with any funky chemicals.

LMAO

 

Did you ever recheck your compression on the engine when warm?

Nope. I just got done changing my clutch and flywheel so I put the misfire on hold for a while.

I recently picked up an ultrasonic cleaner from HFR (Harbor Freight Racing) so maybe this weekend I'll soak all of my injectors in carb cleaner overnight, ultrasonic clean them, and then install the new o-rings I got from MrInjector.