question about unburned fuel

[xt2005bonbon]

I freaked out though when my uppipe was glowing (fire hazard). There was no smoke either. DP did not glow.

[heiche]

Glad the raw fuel issue didn't cause any issues

[xt2005bonbon]

I hope so. Been difficult lately dealing with all these issues. Definitely love/hate relationship with these cars.

[xt2005bonbon]

Another quick update...

 

Getting ready to perform my leak down test. So last night I pulled all the coilpacks and spark plugs out.

The (somewhat new) one I installed in #2 a week ago was wet (fuel). So spark plug in #2 was probably fouled again. Looks like I still have a fuel issue in that cylinder

[heiche]

before you shut it down for the leakdown test, had it been misfiring again on #2?

 

Also, just want to toss out there that sometimes a misfire can present itself as a fouled/wet spark plug.

[xt2005bonbon]

before you shut it down for the leakdown test, had it been misfiring again on #2?

 

Also, just want to toss out there that sometimes a misfire can present itself as a fouled/wet spark plug.

 

On my way home, I was trying to keep the rpm above 3k, where the car was running OK. I was monitoring roughness in all cylinders, FKC, FLKC, A/F correction, A/F Learning, AFR, etc.. Everything looked OK above 3k. But if I had to idle, the A/F Correction was going all over the place (+/-25%), roughness counts were present in all cylinders, although I was getting more in #2. CEL flashed a couple of times while idling and that was it. Then I got home and never turned the car back on. Too scared.

[Max Capacity]

before you shut it down for the leakdown test, had it been misfiring again on #2?

 

Also, just want to toss out there that sometimes a misfire can present itself as a fouled/wet spark plug.

 

 

 

I'm guess you have an injector problem in #2 ?

 

I can't view my pictures here at work, but is there a picture of my exhaust ports in my click here link ?

 

At first thought from post #29 I thought you may have a burnt valve or are running lean in the other cylinders.

[xt2005bonbon]

At this point, I am not sure what is going on really. That's why I have decided to do a leakdown test.

 

As for the valve stem color, I did some searches online and some guys on NASIOC were saying that the whitish color on the valve stems was perfectly normal.. Last night, I had another look at the valve stems and BOTH exhaust valve stems in #2 have black soot on them. But then again, the whole exhaust port has black soot (more than the other 3).

 

As for injector problem in #2, well I posted this and this a couple of weeks ago with no real answers. I essentially noticed that the 'fuel rail injector hole #2' was not perfectly aligned with the hole in the TGV assembly, thereby pinching the small injector oring.

 

I would also note that when I took out the airbox and stuff for spark plug removal, there was still a strong fuel smell in the intake track.

[heiche]

Did you end up replacing the small oring on the #2 injector? On sidefeeds, if the small oring isn't sealing completely (due to a nick in it, or if it's just too old/brittle) then fuel can go directly into the port

[xt2005bonbon]

No, but I put a different injector in it with a small oring that looked fine. I made sure I put some engine oil on both orings before putting this spare injector back in. After that, it ran OK until my drive back from work.

[Max Capacity]

 

I would also note that when I took out the airbox and stuff for spark plug removal, there was still a strong fuel smell in the intake track.

 

 

FWIW, the air box is by #1 plug. If your smelling fuel in the intake tube...how can that be... the injectors are after the throttle body. Just thinking out loud here.

[heiche]

FWIW, the air box is by #1 plug. If your smelling fuel in the intake tube...how can that be... the injectors are after the throttle body. Just thinking out loud here.

 

Maybe if fuel is leaking through the injector (or "around it" if the small oring is bad) it would flood with enough fuel to soak the intake manifold and even get some past the rings into the crankcase. You'd probably smell the fuel vapor everywhere at that point. The intake tract has breather hoses that could be channeling fumes from the crankcase.

 

Sorry to be stuck on the #2 small oring. Is it an oem oring that's in there now? If not, can it be replaced? I figure if there's raw fuel in the #2 cylinder then it's either going through a stuck-open injector (but you swapped it), going "around" the injector via a bad small oring, or the misfires in #2 are so bad that fuel isn't getting properly combusted, and raw fuel is getting left behind.

[xt2005bonbon]

I know.. Like I said, I am confused

 

Then again, remember that when fuel was dumped in cylinder 2, I left the car alone as is for like 1.5 weeks. So probably the intake valves were open in that cylinder and fuel vapor went there ??

[xt2005bonbon]

Sorry to be stuck on the #2 small oring. Is it an oem oring that's in there now? If not, can it be replaced? I figure if there's raw fuel in the #2 cylinder then it's either going through a stuck-open injector (but you swapped it), going "around" the injector via a bad small oring, or the misfires in #2 are so bad that fuel isn't getting properly combusted, and raw fuel is getting left behind.

 

Yes it can be replaced, like 10 bucks for one . Since I had a spare injector with a visually good looking oring, I did not replace the oring.

 

And yeah you're right, if there's a bad seal, then definitely extra fuel would get into the chamber.

 

But if misfire #2 were so bad, i would see it on the btssm. As you know, I am OCD about these things..

[xt2005bonbon]

Another update...

 

was going to finally perform a leakdown test last night. As I was trying to find TDC in cylinder 2, I was underneath the car looking at the exhaust valves getting close. As they were closing, fuel puked once again from the exhaust port . A nice little puddle..

 

So I guess even after swapping injectors, oiling the orings, and carefully putting the spare injector in place, somehow it leaked again . So it looks like the overheating uppipe cat was due to fresh fuel getting burned AT the cat..

 

Now, I have no clue why this is happening (fuel leaking in #2) cause I know I was very meticulous in seating the injector..

 

I am still wondering if the misalignment between the fuel rail and TGV assembly is the cause of the problems I am having (see pic below). Anyone?

 

http://legacygt.com/forums/attachment.php?attachmentid=204459&d=1426094851

[xt2005bonbon]

Bump

[heiche]

That's a puzzler. Not sure on the alignment thing. The smaller o-ring seats in the fuel rail right? (not the tgv manifold below it) If so, I can't think of how fuel would leak out, even with that slight misalignment.

 

But what else could it be? Can you think of anything that changed just before this raw fuel issue started? (mechanical work, new tune, etc, etc)

[xt2005bonbon]

That's a puzzler. Not sure on the alignment thing. The smaller o-ring seats in the fuel rail right? (not the tgv manifold below it) If so, I can't think of how fuel would leak out, even with that slight misalignment

 

When I swapped the injectors the first time, fuel got dumped in cylinder 2 afterwards. I then pulled the injector (which became stuck for some unknown reason) and did notice the small oring was slightly pinched. It appeared that the area where it got pinched was in contact with the spot I am pointing at on the above picture.

 

 

 

But what else could it be? Can you think of anything that changed just before this raw fuel issue started? (mechanical work, new tune, etc, etc)

 

Car was just fine before swapping injectors (apart from having some roughness in #2 when warm at idle). That's why I began troubleshooting it by swapping spark plugs, coil packs, and then injectors. So right before I swapped injectors, I swapped both spark plugs and coil packs. Engine ran OK when I did that first swap. Roughness did not move. So that's why I swapped injectors right after.

 

I am tempted to try to realign the fuel rail to the TGV assembly but I've never done that before..

Only other things I can think of to do is send my injectors for cleaning. They'll then put new orings and stuff.

 

 

Well, maybe I should ask the following question: is a stuck open injector OR a defective oring the only reasons to find raw fuel in a cylinder?

[heiche]

realigning might not be a bad idea.

 

what else can cause raw fuel in a cylinder? a few thoughts come to mind, probably all of them very rare:

-short to ground in the injector wiring harness (on the "-" side) will open the injector

-bad ecu could cause the injector to hang open

-even a bad tune (really bad tune) can cause it if someone fat-fingered a injector compensation value

 

this being said, my guess is on something physically wrong with the smaller oring seating in the fuel rail.

[xt2005bonbon]

thanks heiche for your suggestions.

 

Yeah I am also leaning towards the smaller oring. Man what a pain..

 

Now here is the issue. I did not expect that fuel was going to leak again. So I did not de-pressurize the fuel lines. And right now, spark plugs, exhaust manifold and uppipe are off the car. So no way I can crank the engine to get rid of the fuel.

So do you guys know of a different method to do that, so that I can take the injectors out?

[rhino6303]

So do you guys know of a different method to do that, so that I can take the injectors out?

 

Let the car sit overnight with the gas cap off. Should be depressurized enough after 24 hours or so to remove the lines. I've done this several times with several cars without having fuel spray everywhere.

 

Just be sure to put a rag over the injectors when removing them.

[JmP6889928]

Loosen the clamp on the hardline to hose at the strut tower and then wrap it in a big fluffy rag, and twist it loose and soak up the gas. It will only be several tablespoons and it will just go into the rag. Have done many that way and it's easy and you have a rag full of clean gas you can use to wipe down parts with too.

[xt2005bonbon]

Let the car sit overnight with the gas cap off. Should be depressurized enough after 24 hours or so to remove the lines. I've done this several times with several cars without having fuel spray everywhere.

 

Just be sure to put a rag over the injectors when removing them.

 

Loosen the clamp on the hardline to hose at the strut tower and then wrap it in a big fluffy rag, and twist it loose and soak up the gas. It will only be several tablespoons and it will just go into the rag. Have done many that way and it's easy and you have a rag full of clean gas you can use to wipe down parts with too.

 

Thank a lot guys. I will follow your advice. Fwiw, the car has been sitting for two weeks now. I would think that should help as well.

[heiche]

any updates?

[xt2005bonbon]

none . My plan this week was to do my leakdown test. But the supplied hose with my leakdown tester is leaking . So I can't do the test.

Tomorrow, I may pull the injector out once again, and try realigning the fuel rail..